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Probability-and-statistics/191415: You are given the probability that event A occurs. Find P (not A), the probability that event A does not occur
1 solutions

Answer 143640 by jim_thompson5910(28476) About Me  on 2009-04-15 23:51:08 (Show Source):
You can put this solution on YOUR website!
If P%28A%29=x, then P%28NOT_A%29=1-x. In other words, just subtract the given probability from 1 to get the probability that A will NOT occur.


Permutations/191392: This question is from textbook MATHEMATICS: Structure and Method, Course 2
I DON'T KNOW WHAT TO DO! HELP ME HERE IS THE QUESTION-
Philip wishes to check out two books out of his school library. If the library contains 800 books, in how many ways might Philip get his choice of books?
PLEASE RESPOND IMMEDIATELY!!!!!!!!!!!IT'S DUE TOMMOROW!!!!!!!!!!!!!!!!!!!!!!!!!
1 solutions

Answer 143630 by jim_thompson5910(28476) About Me  on 2009-04-15 21:49:28 (Show Source):
You can put this solution on YOUR website!
For the first selection, you have a choice of 800 books. Once that selection has been made, you now have 799 books left over. So if the order matters, then you simply multiply 800 by 799 to get:

800 x 799 = 639,200


So there are 639,200 different ways to choose two books (where the order of the books matters).

----------------------------------------------

If the order of the books does NOT matter, then simply divide by 2 (since xy is the same as yx) to get

639,200/2=319,600


So there are 319,600 different ways to choose two books if the order does NOT matter.


Linear-systems/191384: This question is from textbook algebra 1
the question (i have to do 11 of these) is:
"Determine whether each system is consistent or inconsistent by solving it graphically and algebraically"
{ y=-4x+6
{ 2y=-8x-8
i tried doing "step 1: 2(-4x+6)=-8x-8 step 2: -8x+12=-8x-8 step 3: 0x+12=-8"
and i know it isn't right, could someone explain how you find the answer please.
thanks!!


1 solutions

Answer 143624 by jim_thompson5910(28476) About Me  on 2009-04-15 21:20:52 (Show Source):
You can put this solution on YOUR website!
You have the correct steps. Since the equation 12=-8 is NOT true, this means that there are NO solutions. So the system is inconsistent.


Graphs/191381: Hello, can you please help me solve this problem.
--Solve the system by using the substitution method--
x%5E2%2By%5E2=113 with this under it x-y=1
1 solutions

Answer 143621 by jim_thompson5910(28476) About Me  on 2009-04-15 20:54:45 (Show Source):
You can put this solution on YOUR website!
x-y=1 Start with the second equation.


x=y%2B1 Add "y" to both sides.


x%5E2%2By%5E2=113 Move onto the first equation


%28y%2B1%29%5E2%2By%5E2=113 Plug in x=y%2B1


y%5E2%2B2y%2B1%2By%5E2=113 FOIL


y%5E2%2B2y%2B1%2By%5E2-113=0 Subtract 113 from both sides.


2y%5E2%2B2y-112=0 Combine like terms.


Notice we have a quadratic equation in the form of ay%5E2%2Bby%2Bc where a=2, b=2, and c=-112


Let's use the quadratic formula to solve for y


y+=+%28-b+%2B-+sqrt%28+b%5E2-4ac+%29%29%2F%282a%29 Start with the quadratic formula


y+=+%28-%282%29+%2B-+sqrt%28+%282%29%5E2-4%282%29%28-112%29+%29%29%2F%282%282%29%29 Plug in a=2, b=2, and c=-112


y+=+%28-2+%2B-+sqrt%28+4-4%282%29%28-112%29+%29%29%2F%282%282%29%29 Square 2 to get 4.


y+=+%28-2+%2B-+sqrt%28+4--896+%29%29%2F%282%282%29%29 Multiply 4%282%29%28-112%29 to get -896


y+=+%28-2+%2B-+sqrt%28+4%2B896+%29%29%2F%282%282%29%29 Rewrite sqrt%284--896%29 as sqrt%284%2B896%29


y+=+%28-2+%2B-+sqrt%28+900+%29%29%2F%282%282%29%29 Add 4 to 896 to get 900


y+=+%28-2+%2B-+sqrt%28+900+%29%29%2F%284%29 Multiply 2 and 2 to get 4.


y+=+%28-2+%2B-+30%29%2F%284%29 Take the square root of 900 to get 30.


y+=+%28-2+%2B+30%29%2F%284%29 or y+=+%28-2+-+30%29%2F%284%29 Break up the expression.


y+=+%2828%29%2F%284%29 or y+=++%28-32%29%2F%284%29 Combine like terms.


y+=+7 or y+=+-8 Simplify.


So the answers for "y" are y+=+7 or y+=+-8



Now take these solutions and plug them into x=y%2B1 to find "x"

x=y%2B1=7%2B1=8

So when x=8, y=7


x=y%2B1=-8%2B1=-7

So when x=-7, y=-8



So the solutions as ordered pairs are (8,7) or (-7,-8)


logarithm/191371: Question: Write an exponential function, y=ab^x for a graph that includes points at (1, 12) and (2, 36).
I do not understand how to find this. Can you please show me the steps and answer?
1 solutions

Answer 143618 by jim_thompson5910(28476) About Me  on 2009-04-15 20:49:24 (Show Source):
You can put this solution on YOUR website!
y=ab%5Ex Start with the given equation.


12=ab%5E%281%29 Plug in x=1 and y=12. These are the x and y coordinates to the point (1,12)


12=ab Simplify


12%2Fa=b Divide both sides by "a".


b=12%2Fa Rearrange the equation


------------------------

y=ab%5Ex Go back to the given equation.


36=ab%5E%282%29 Plug in x=2 and y=36. These are the x and y coordinates to the point (2,36)


36=a%2812%2Fa%29%5E%282%29 Plug in b=12%2Fa


36=a%28144%2Fa%5E2%29 Square 12%2Fa to get 144%2Fa%5E2


36=%28144a%29%2F%28a%5E2%29 Multiply


36=144%2Fa Reduce


36a=144 Multiply both sides by "a".


a=144%2F36 Divide both sides by 36.


a=4 Reduce

-----------------------

b=12%2Fa Go back to the first isolated equation


b=12%2F4 Plug in a=4


b=3 Reduce


So the exponential equation is y=4%2A3%5Ex


Polynomials-and-rational-expressions/191261: Please help me factorize and state the roots of the following polynomial. Please, I beg you, I need to know how to to this and would really appreciate whatever help I can get. This was a take home assignment. Thanks.
P(x)=4x^7+28x^6+27x^5-203x^4-591x^3-431x^2+146x+120
1 solutions

Answer 143585 by jim_thompson5910(28476) About Me  on 2009-04-15 17:04:37 (Show Source):
You can put this solution on YOUR website!
Wow, this is as long as it gets (well I hope so anyway...). Here are two ways to do this:

Method #1:

Use the rational root theorem to find all of the possible roots and test EVERY possible root to see if it is actually a root. Since the degree of the equation is 7, this means that once you find 7 roots, then you don't need to check any more possible roots.

Here's where this method gets really tedious: there are A LOT of possible roots (48 in total)


But, here's how to find them:


Any rational zero can be found through this equation

where p and q are the factors of the last and first coefficients


So let's list the factors of 120 (the last coefficient):



Now let's list the factors of 4 (the first coefficient):



Now let's divide each factor of the last coefficient by each factor of the first coefficient









Now simplify

These are all the distinct rational zeros of the function that could occur





Once you have all of the possible rational roots, either plug them in directly or use synthetic division to determine which ones are actually roots.







Method #2:


Since the first method seems like a lot of busy work (which it is), just use a graphing calculator to find some of the roots, and then use those roots to find other roots (using synthetic division). Eventually, you'll reduce that massive polynomial to a quadratic which you can solve using the quadratic formula.





If you're completely stuck, then repost or email me. By the way, the 7 roots are: 3, -1/2, 1/2, -4, -2, -2+i, -2-i


Also, 4x%5E7%2B28x%5E6%2B27x%5E5-203x%5E4-591x%5E3-431x%5E2%2B146x%2B120 completely factors (over the reals) to %28x-3%29%282x%2B1%29%282x-1%29%28x%2B4%29%28x%2B2%29%28x%5E2%2B4x%2B5%29


In other words,


Radicals/191291: This question is from textbook
I need some help with a problem that states I need to rationalize the denominator. The problem is (square(3)-square(4))/(square(3)+square(4)). I did the steps that it said to, but my answer does not match the answer in the book. When I solved the problem I got (square(3)-square(4)(square(3)+square(4) with a - 1 for the denominator?
What am I doing wrong?
Any help would be greatly appreciated!
1 solutions

Answer 143582 by jim_thompson5910(28476) About Me  on 2009-04-15 16:46:51 (Show Source):
You can put this solution on YOUR website!
%28sqrt%283%29-sqrt%284%29%29%2F%28sqrt%283%29%2Bsqrt%284%29%29 Start with the given expression.


Multiply both the numerator and denominator by sqrt%283%29-sqrt%284%29


Note: sqrt%283%29-sqrt%284%29 is the conjugate of the denominator sqrt%283%29%2Bsqrt%284%29. Multiplying these two expressions yields a rational expression


FOIL the denominator (use the difference of squares formula)



FOIL the numerator (use the perfect square formula)


%283-2%2Asqrt%284%29%2Asqrt%283%29%2B4%29%2F%283-4%29 Square each term


%283-2%2Asqrt%2812%29%2B4%29%2F%283-4%29 Combine and multiply the roots.


%287-2%2Asqrt%2812%29%29%2F%28-1%29 Combine like terms.


%287-2%2A2%2Asqrt%283%29%29%2F%28-1%29 Simplify sqrt%2812%29 to get 2%2Asqrt%283%29


%287-4%2Asqrt%283%29%29%2F%28-1%29 Multiply


-7%2B4%2Asqrt%283%29 Reduce


So %28sqrt%283%29-sqrt%284%29%29%2F%28sqrt%283%29%2Bsqrt%284%29%29=-7%2B4%2Asqrt%283%29


Quadratic_Equations/191307: Solve for x
If the solutions are complex numbers, then give soulutions in the usual a + bi form
a) x^2 - 6x + 9 = 0
b) x^2 + 4x + 7 = 0
1 solutions

Answer 143581 by jim_thompson5910(28476) About Me  on 2009-04-15 16:37:42 (Show Source):
You can put this solution on YOUR website!
a)



x%5E2-6x%2B9=0 Start with the given equation.


Notice we have a quadratic equation in the form of ax%5E2%2Bbx%2Bc where a=1, b=-6, and c=9


Let's use the quadratic formula to solve for x


x+=+%28-b+%2B-+sqrt%28+b%5E2-4ac+%29%29%2F%282a%29 Start with the quadratic formula


x+=+%28-%28-6%29+%2B-+sqrt%28+%28-6%29%5E2-4%281%29%289%29+%29%29%2F%282%281%29%29 Plug in a=1, b=-6, and c=9


x+=+%286+%2B-+sqrt%28+%28-6%29%5E2-4%281%29%289%29+%29%29%2F%282%281%29%29 Negate -6 to get 6.


x+=+%286+%2B-+sqrt%28+36-4%281%29%289%29+%29%29%2F%282%281%29%29 Square -6 to get 36.


x+=+%286+%2B-+sqrt%28+36-36+%29%29%2F%282%281%29%29 Multiply 4%281%29%289%29 to get 36


x+=+%286+%2B-+sqrt%28+0+%29%29%2F%282%281%29%29 Subtract 36 from 36 to get 0


x+=+%286+%2B-+sqrt%28+0+%29%29%2F%282%29 Multiply 2 and 1 to get 2.


x+=+%286+%2B-+0%29%2F%282%29 Take the square root of 0 to get 0.


x+=+%286+%2B+0%29%2F%282%29 or x+=+%286+-+0%29%2F%282%29 Break up the expression.


x+=+%286%29%2F%282%29 or x+=++%286%29%2F%282%29 Combine like terms.


x+=+3 or x+=+3 Simplify.


So solution is x+=+3


---------------------------------------------------------------


b)



x%5E2%2B4x%2B7=0 Start with the given equation.


Notice we have a quadratic equation in the form of ax%5E2%2Bbx%2Bc where a=1, b=4, and c=7


Let's use the quadratic formula to solve for x


x+=+%28-b+%2B-+sqrt%28+b%5E2-4ac+%29%29%2F%282a%29 Start with the quadratic formula


x+=+%28-%284%29+%2B-+sqrt%28+%284%29%5E2-4%281%29%287%29+%29%29%2F%282%281%29%29 Plug in a=1, b=4, and c=7


x+=+%28-4+%2B-+sqrt%28+16-4%281%29%287%29+%29%29%2F%282%281%29%29 Square 4 to get 16.


x+=+%28-4+%2B-+sqrt%28+16-28+%29%29%2F%282%281%29%29 Multiply 4%281%29%287%29 to get 28


x+=+%28-4+%2B-+sqrt%28+-12+%29%29%2F%282%281%29%29 Subtract 28 from 16 to get -12


x+=+%28-4+%2B-+sqrt%28+-12+%29%29%2F%282%29 Multiply 2 and 1 to get 2.


x+=+%28-4+%2B-+2i%2Asqrt%283%29%29%2F%282%29 Simplify the square root (note: If you need help with simplifying square roots, check out this solver)


x+=+%28-4%29%2F%282%29+%2B-+%282i%2Asqrt%283%29%29%2F%282%29 Break up the fraction.


x+=+-2+%2B-+sqrt%283%29%2Ai Reduce.


x+=+-2%2Bsqrt%283%29%2Ai or x+=+-2-sqrt%283%29%2Ai Break up the expression.


So the answers are x+=+-2%2Bsqrt%283%29%2Ai or x+=+-2-sqrt%283%29%2Ai where i=sqrt%28-1%29

Note: the solutions are in the form x=a%2Bbi or x=a-bi where a=-2 and b=sqrt%283%29


expressions/191309: (7-2)/5
1 solutions

Answer 143579 by jim_thompson5910(28476) About Me  on 2009-04-15 16:35:13 (Show Source):


Equations/191305: X+3/x-1=x+4/x-5
(x+3)(x-5)=(x-1)(x+4)
x^2+3x-15=x^2-x-4
x^2+4x+11=x^2
1 solutions

Answer 143578 by jim_thompson5910(28476) About Me  on 2009-04-15 16:34:06 (Show Source):
You can put this solution on YOUR website!
%28x%2B3%29%2F%28x-1%29=%28x%2B4%29%2F%28x-5%29 Start with the given equation.


%28x%2B3%29%28x-5%29=%28x-1%29%28x%2B4%29 Cross multiply


x%5E2-2x-15=x%5E2%2B3x-4 FOIL (this is where you made a mistake)


x%5E2-2x-15-x%5E2-3x%2B4=0 Get everything to the left side


-5x-11=0 Combine like terms.


-5x=0%2B11 Add 11 to both sides.


-5x=11 Combine like terms on the right side.


x=%2811%29%2F%28-5%29 Divide both sides by -5 to isolate x.


x=-11%2F5 Reduce.


----------------------------------------------------------------------

Answer:

So the answer is x=-11%2F5 which in decimal form is x=-2.2.


Polynomials-and-rational-expressions/191271: Convert the number to scientific notation.
1,934,000,000
1 solutions

Answer 143550 by jim_thompson5910(28476) About Me  on 2009-04-15 14:00:06 (Show Source):
You can put this solution on YOUR website!
Take the decimal point and place it in between the 1 and the 9. Take note that you have to move the decimal point 9 places to the right. So the exponent is 9


So this means that:



decimal-numbers/191258: Write the number without exponents.
2.78x10^10
1 solutions

Answer 143546 by jim_thompson5910(28476) About Me  on 2009-04-15 13:38:00 (Show Source):
You can put this solution on YOUR website!
Simply move the decimal point 10 spots to the right to get:





Complex_Numbers/191251: This question is from textbook algebra and trigonometry structure and method book 2
Find the number of times r is a root of P(x)=0.
P(x)= x^4+4x^3-16x-16; r=-2
i found the depressed eruation twice but the numbers were all messed up. please help and explain.
1 solutions

Answer 143544 by jim_thompson5910(28476) About Me  on 2009-04-15 13:12:17 (Show Source):
You can put this solution on YOUR website!
First, perform synthetic division where -2 is the test zero (let me know if you need help with synthetic division)

-2 | 1   4   0   -16   -16
   |    -2  -4     8    16
   ------------------------
     1   2  -4    -8     0



Since the last number in the bottom row is zero, this means that the remainder is 0. So -2 is a root of P%28x%29=+x%5E4%2B4x%5E3-16x-16

The first 4 numbers form the depressed polynomial x%5E3%2B2x%5E2-4x-8. This means that x%5E4%2B4x%5E3-16x-16=%28x%2B2%29%28x%5E3%2B2x%5E2-4x-8%29
=================================


Now perform synthetic division on x%5E3%2B2x%5E2-4x-8 using the same test zero:

-2 | 1   2  -4    -8   
   |    -2   0     8   
   ------------------
     1   0  -4     0   


Notice how the last number in the bottom row is 0. So -2 is a root of x%5E3%2B2x%5E2-4x-8. So far, r=-2 is a root of multiplicity 2 (ie -2 is a root twice).


The first 3 numbers in the bottom row form the new polynomial x%5E2-4. This tells us that x%5E3%2B2x%5E2-4x-8=%28x%2B2%29%28x%5E2-4%29


So

=================================


Now perform synthetic division on the polynomial x%5E2-4
-2 | 1   0  -4     
   |    -2   4    
   ------------
     1  -2   0




So -2 is a root of x%5E2-4. So this means that r=-2 is a root of multiplicity 3 (ie -2 is a root three times).


The first two numbers in the bottom row form the new polynomial: x-2


Now because -2 is NOT a root of x-2, this means that we can stop looking for more roots of -2.


So

Or in other words, x%5E4%2B4x%5E3-16x-16=%28x%2B2%29%28x%2B2%29%28x%2B2%29%28x-2%29


Notice how the factor x%2B2 is repeated 3 times, this supports our conclusion that r=-2 is a root of multiplicity 3


Equations/191248: Can someone tell me why 3.14 and 1/6 are irrational numbers? Thank You!
1 solutions

Answer 143534 by jim_thompson5910(28476) About Me  on 2009-04-15 11:23:34 (Show Source):
You can put this solution on YOUR website!
They aren't irrational numbers (unless you've made a typo somewhere). Since 3.14=314%2F100 and 1%2F6 can both be represented by a fraction of whole numbers, this means that 3.14 and 1%2F6 are both rational numbers.


Polynomials-and-rational-expressions/191192: 4 x+20/x^2+5x=
1 solutions

Answer 143494 by jim_thompson5910(28476) About Me  on 2009-04-14 23:38:59 (Show Source):
You can put this solution on YOUR website!

%284x%2B20%29%2F%28x%5E2%2B5x%29 Start with the given expression.


%284%28x%2B5%29%29%2F%28x%5E2%2B5x%29 Factor 4x%2B20 to get 4%28x%2B5%29.


%284%28x%2B5%29%29%2F%28x%2A%28x%2B5%29%29 Factor x%5E2%2B5x to get x%2A%28x%2B5%29.


%284%2Ahighlight%28%28x%2B5%29%29%29%2F%28x%2Ahighlight%28%28x%2B5%29%29%29 Highlight the common terms.


%284%2Across%28%28x%2B5%29%29%29%2F%28x%2Across%28%28x%2B5%29%29%29 Cancel out the common terms.


4%2Fx Simplify.


So %284x%2B20%29%2F%28x%5E2%2B5x%29 simplifies to 4%2Fx.


In other words, %284x%2B20%29%2F%28x%5E2%2B5x%29=4%2Fx where x%3C%3E-5 or x%3C%3E0


Equations/191061: This question is from textbook saxon algebra2
solve.
3x/x^2-1=5/x
I worked it out to:
2(x-5)(x+1)
Is this correct?
1 solutions

Answer 143449 by jim_thompson5910(28476) About Me  on 2009-04-14 15:41:00 (Show Source):
You can put this solution on YOUR website!
I'm assuming that the equation is %283x%29%2F%28x%5E2-1%29=5%2Fx.


%283x%29%2F%28x%5E2-1%29=5%2Fx Start with the given equation


%283x%29%28x%29=5%28x%5E2-1%29 Cross multiply


3x%5E2=5x%5E2-5 Distribute and multiply


3x%5E2-5x%5E2=-5 Subtract 5x%5E2 from both sides


-2x%5E2=-5 Combine like terms.


x%5E2=-5%2F%28-2%29 Divide both sides by -2


x%5E2=5%2F2 Reduce


x=%27%27%2B-sqrt%285%2F2%29 Take the square root of both sides



x=sqrt%285%2F2%29 or x=-sqrt%285%2F2%29 Break up the "plus/minus" to form 2 separate equations.


x=sqrt%2810%29%2F2 or x=-sqrt%2810%29%2F2 Simplify the square root.


So the solutions are x=sqrt%2810%29%2F2 or x=-sqrt%2810%29%2F2


Polynomials-and-rational-expressions/191090: factor by grouping
5x^2-12x+7
1 solutions

Answer 143448 by jim_thompson5910(28476) About Me  on 2009-04-14 15:30:04 (Show Source):
You can put this solution on YOUR website!

Looking at the expression 5x%5E2-12x%2B7, we can see that the first coefficient is 5, the second coefficient is -12, and the last term is 7.


Now multiply the first coefficient 5 by the last term 7 to get %285%29%287%29=35.


Now the question is: what two whole numbers multiply to 35 (the previous product) and add to the second coefficient -12?


To find these two numbers, we need to list all of the factors of 35 (the previous product).


Factors of 35:
1,5,7,35
-1,-5,-7,-35


Note: list the negative of each factor. This will allow us to find all possible combinations.


These factors pair up and multiply to 35.
1*35
5*7
(-1)*(-35)
(-5)*(-7)

Now let's add up each pair of factors to see if one pair adds to the middle coefficient -12:


First NumberSecond NumberSum
1351+35=36
575+7=12
-1-35-1+(-35)=-36
-5-7-5+(-7)=-12



From the table, we can see that the two numbers -5 and -7 add to -12 (the middle coefficient).


So the two numbers -5 and -7 both multiply to 35 and add to -12


Now replace the middle term -12x with -5x-7x. Remember, -5 and -7 add to -12. So this shows us that -5x-7x=-12x.


5x%5E2%2Bhighlight%28-5x-7x%29%2B7 Replace the second term -12x with -5x-7x.


%285x%5E2-5x%29%2B%28-7x%2B7%29 Group the terms into two pairs.


5x%28x-1%29%2B%28-7x%2B7%29 Factor out the GCF 5x from the first group.


5x%28x-1%29-7%28x-1%29 Factor out 7 from the second group. The goal of this step is to make the terms in the second parenthesis equal to the terms in the first parenthesis.


%285x-7%29%28x-1%29 Combine like terms. Or factor out the common term x-1

---------------------------------------------


Answer:


So 5x%5E2-12x%2B7 factors to %285x-7%29%28x-1%29.


Note: you can check the answer by FOILing %285x-7%29%28x-1%29 to get 5x%5E2-12x%2B7 or by graphing the original expression and the answer (the two graphs should be identical).


Polynomials-and-rational-expressions/191092: factor by grouping
4x^2-4x-3
1 solutions

Answer 143447 by jim_thompson5910(28476) About Me  on 2009-04-14 15:28:19 (Show Source):
You can put this solution on YOUR website!

Looking at the expression 4x%5E2-4x-3, we can see that the first coefficient is 4, the second coefficient is -4, and the last term is -3.


Now multiply the first coefficient 4 by the last term -3 to get %284%29%28-3%29=-12.


Now the question is: what two whole numbers multiply to -12 (the previous product) and add to the second coefficient -4?


To find these two numbers, we need to list all of the factors of -12 (the previous product).


Factors of -12:
1,2,3,4,6,12
-1,-2,-3,-4,-6,-12


Note: list the negative of each factor. This will allow us to find all possible combinations.


These factors pair up and multiply to -12.
1*(-12)
2*(-6)
3*(-4)
(-1)*(12)
(-2)*(6)
(-3)*(4)

Now let's add up each pair of factors to see if one pair adds to the middle coefficient -4:


First NumberSecond NumberSum
1-121+(-12)=-11
2-62+(-6)=-4
3-43+(-4)=-1
-112-1+12=11
-26-2+6=4
-34-3+4=1



From the table, we can see that the two numbers 2 and -6 add to -4 (the middle coefficient).


So the two numbers 2 and -6 both multiply to -12 and add to -4


Now replace the middle term -4x with 2x-6x. Remember, 2 and -6 add to -4. So this shows us that 2x-6x=-4x.


4x%5E2%2Bhighlight%282x-6x%29-3 Replace the second term -4x with 2x-6x.


%284x%5E2%2B2x%29%2B%28-6x-3%29 Group the terms into two pairs.


2x%282x%2B1%29%2B%28-6x-3%29 Factor out the GCF 2x from the first group.


2x%282x%2B1%29-3%282x%2B1%29 Factor out 3 from the second group. The goal of this step is to make the terms in the second parenthesis equal to the terms in the first parenthesis.


%282x-3%29%282x%2B1%29 Combine like terms. Or factor out the common term 2x%2B1

---------------------------------------------


Answer:


So 4x%5E2-4x-3 factors to %282x-3%29%282x%2B1%29.


Note: you can check the answer by FOILing %282x-3%29%282x%2B1%29 to get 4x%5E2-4x-3 or by graphing the original expression and the answer (the two graphs should be identical).


logarithm/191051: This question is from textbook
Given f(x) = e^-2x + 1, evaluate the following. Round to the nearest ten-thousandth.
f(-1)
f(3)
f(-2)
Show your work here:
f(-1)=e -2(-1)+1=x-1
f(-1)=e^2+1
f(-1)=7.389+1
f(-1) = 8.389

1 solutions

Answer 143446 by jim_thompson5910(28476) About Me  on 2009-04-14 15:27:15 (Show Source):
You can put this solution on YOUR website!
I'm assuming that the function is f%28x%29=e%5E%28-2x%29%2B1.


Evaluating f(-1):


f%28x%29=e%5E%28-2x%29%2B1 Start with the given equation.


f%28-1%29=e%5E%28-2%28-1%29%29%2B1 Plug in x=-1.


f%28-1%29=e%5E%282%29%2B1 Multiply -2 and -1 to get 2.


f%28-1%29=7.3891%2B1 Raise "e" to the 2nd power to get 7.3891 (note: this value is approximate).


f%28-1%29=8.3891 Add 1 to 7.3891 to get 8.3891.


----------------------------


Evaluating f(3):


f%28x%29=e%5E%28-2x%29%2B1 Start with the given equation.


f%283%29=e%5E%28-2%283%29%29%2B1 Plug in x=3.


f%283%29=e%5E%28-6%29%2B1 Multiply -2 and 3 to get -6.


f%283%29=0.0025%2B1 Raise "e" to the -6th power to get 0.0025 (note: this value is approximate).


f%283%29=1.0025 Add 1 to 0.0025 to get 1.0025.


----------------------------


Evaluating f(-2):


f%28x%29=e%5E%28-2x%29%2B1 Start with the given equation.


f%28-2%29=e%5E%28-2%28-2%29%29%2B1 Plug in x=-2.


f%28-2%29=e%5E%284%29%2B1 Multiply -2 and -2 to get 4.


f%28-2%29=54.5982%2B1 Raise "e" to the 4th power to get 54.5982 (note: this value is approximate).


f%28-2%29=55.5982 Add 1 to 54.5982 to get 55.5982.




Exponential-and-logarithmic-functions/191078: Please help me solve this equation
5-5 Completing the Square
Solving a quadratic equation if the coefficient of x^2 is NOT 1

4x^2+24x-8=0
1 solutions

Answer 143444 by jim_thompson5910(28476) About Me  on 2009-04-14 15:15:06 (Show Source):
You can put this solution on YOUR website!
First, let's complete the square for the left side of the equation 4x%5E2%2B24x-8=0


4x%5E2%2B24x-8 Start with the given expression.


4%28x%5E2%2B6x-2%29 Factor out the x%5E2 coefficient 4. This step is very important: the x%5E2 coefficient must be equal to 1.


Take half of the x coefficient 6 to get 3. In other words, %281%2F2%29%286%29=3.


Now square 3 to get 9. In other words, %283%29%5E2=%283%29%283%29=9


4%28x%5E2%2B6x%2Bhighlight%289-9%29-2%29 Now add and subtract 9 inside the parenthesis. Make sure to place this after the "x" term. Notice how 9-9=0. So the expression is not changed.


4%28%28x%5E2%2B6x%2B9%29-9-2%29 Group the first three terms.


4%28%28x%2B3%29%5E2-9-2%29 Factor x%5E2%2B6x%2B9 to get %28x%2B3%29%5E2.


4%28%28x%2B3%29%5E2-11%29 Combine like terms.


4%28x%2B3%29%5E2%2B4%28-11%29 Distribute.


4%28x%2B3%29%5E2-44 Multiply.


So after completing the square, 4x%5E2%2B24x-8 transforms to 4%28x%2B3%29%5E2-44. So 4x%5E2%2B24x-8=4%28x%2B3%29%5E2-44.


So 4x%5E2%2B24x-8=0 is equivalent to 4%28x%2B3%29%5E2-44=0.




-----------------------------------------------------------


Now let's solve 4%28x%2B3%29%5E2-44=0


4%28x%2B3%29%5E2-44=0 Start with the given equation.


4%28x%2B3%29%5E2=44 Add 44 to both sides


%28x%2B3%29%5E2=%2844%29%2F%284%29 Divide both sides by 4.


%28x%2B3%29%5E2=11 Reduce.


x%2B3=%27%27%2B-sqrt%2811%29 Take the square root of both sides.


x%2B3=sqrt%2811%29 or x%2B3=-sqrt%2811%29 Break up the "plus/minus" to form two equations.


x=-3%2Bsqrt%2811%29 or x=-3-sqrt%2811%29 Subtract 3 from both sides.


--------------------------------------


Answer:


So the solutions are x=-3%2Bsqrt%2811%29 or x=-3-sqrt%2811%29.



Polynomials-and-rational-expressions/191084: Please help me solve this equation
5-5 Completing the Square
Solving a quadratic equation if the coefficient of x^2 is NOT 1

3x^2+12x-9=0
1 solutions

Answer 143443 by jim_thompson5910(28476) About Me  on 2009-04-14 15:10:52 (Show Source):
You can put this solution on YOUR website!
First, let's complete the square for the left side of the equation 3x%5E2%2B12x-9=0



3x%5E2%2B12x-9 Start with the given expression.


3%28x%5E2%2B4x-3%29 Factor out the x%5E2 coefficient 3. This step is very important: the x%5E2 coefficient must be equal to 1.


Take half of the x coefficient 4 to get 2. In other words, %281%2F2%29%284%29=2.


Now square 2 to get 4. In other words, %282%29%5E2=%282%29%282%29=4


3%28x%5E2%2B4x%2Bhighlight%284-4%29-3%29 Now add and subtract 4 inside the parenthesis. Make sure to place this after the "x" term. Notice how 4-4=0. So the expression is not changed.


3%28%28x%5E2%2B4x%2B4%29-4-3%29 Group the first three terms.


3%28%28x%2B2%29%5E2-4-3%29 Factor x%5E2%2B4x%2B4 to get %28x%2B2%29%5E2.


3%28%28x%2B2%29%5E2-7%29 Combine like terms.


3%28x%2B2%29%5E2%2B3%28-7%29 Distribute.


3%28x%2B2%29%5E2-21 Multiply.


So after completing the square, 3x%5E2%2B12x-9 transforms to 3%28x%2B2%29%5E2-21. So 3x%5E2%2B12x-9=3%28x%2B2%29%5E2-21.


So 3x%5E2%2B12x-9=0 is equivalent to 3%28x%2B2%29%5E2-21=0.


-----------------------------------------------------------


Now let's solve 3%28x%2B2%29%5E2-21=0


3%28x%2B2%29%5E2-21=0 Start with the given equation.


3%28x%2B2%29%5E2=21 Add 21 to both sides


%28x%2B2%29%5E2=%2821%29%2F%283%29 Divide both sides by 3.


%28x%2B2%29%5E2=7 Reduce.


x%2B2=%27%27%2B-sqrt%287%29 Take the square root of both sides. (note: don't forget the "plus/minus")


x%2B2=sqrt%287%29 or x%2B2=-sqrt%287%29 Break up the "plus/minus" to form two equations.


x=-2%2Bsqrt%287%29 or x=-2-sqrt%287%29 Subtract 2 from both sides.


--------------------------------------


Answer:


So the solutions are x=-2%2Bsqrt%287%29 or x=-2-sqrt%287%29.


Exponential-and-logarithmic-functions/191085: Please help me solve this equation
5-5 Completing the Square
Solving a quadratic equation if the coefficient of x^2 is NOT 1

3x^2+12x-9=0
1 solutions

Answer 143442 by jim_thompson5910(28476) About Me  on 2009-04-14 15:09:51 (Show Source):
You can put this solution on YOUR website!
First, let's complete the square for the left side of the equation 3x%5E2%2B12x-9=0



3x%5E2%2B12x-9 Start with the given expression.


3%28x%5E2%2B4x-3%29 Factor out the x%5E2 coefficient 3. This step is very important: the x%5E2 coefficient must be equal to 1.


Take half of the x coefficient 4 to get 2. In other words, %281%2F2%29%284%29=2.


Now square 2 to get 4. In other words, %282%29%5E2=%282%29%282%29=4


3%28x%5E2%2B4x%2Bhighlight%284-4%29-3%29 Now add and subtract 4 inside the parenthesis. Make sure to place this after the "x" term. Notice how 4-4=0. So the expression is not changed.


3%28%28x%5E2%2B4x%2B4%29-4-3%29 Group the first three terms.


3%28%28x%2B2%29%5E2-4-3%29 Factor x%5E2%2B4x%2B4 to get %28x%2B2%29%5E2.


3%28%28x%2B2%29%5E2-7%29 Combine like terms.


3%28x%2B2%29%5E2%2B3%28-7%29 Distribute.


3%28x%2B2%29%5E2-21 Multiply.


So after completing the square, 3x%5E2%2B12x-9 transforms to 3%28x%2B2%29%5E2-21. So 3x%5E2%2B12x-9=3%28x%2B2%29%5E2-21.


So 3x%5E2%2B12x-9=0 is equivalent to 3%28x%2B2%29%5E2-21=0.


-----------------------------------------------------------


Now let's solve 3%28x%2B2%29%5E2-21=0


3%28x%2B2%29%5E2-21=0 Start with the given equation.


3%28x%2B2%29%5E2=21 Add 21 to both sides


%28x%2B2%29%5E2=%2821%29%2F%283%29 Divide both sides by 3.


%28x%2B2%29%5E2=7 Reduce.


x%2B2=%27%27%2B-sqrt%287%29 Take the square root of both sides. (note: don't forget the "plus/minus")


x%2B2=sqrt%287%29 or x%2B2=-sqrt%287%29 Break up the "plus/minus" to form two equations.


x=-2%2Bsqrt%287%29 or x=-2-sqrt%287%29 Subtract 2 from both sides.


--------------------------------------


Answer:


So the solutions are x=-2%2Bsqrt%287%29 or x=-2-sqrt%287%29.


Graphs/190944: A Line parallel to -3x + 2y = 9 and contains points (-2,1)
How do I set this up??
1 solutions

Answer 143362 by jim_thompson5910(28476) About Me  on 2009-04-13 19:39:06 (Show Source):
You can put this solution on YOUR website!

-3x+%2B+2y+=+9 Start with the given equation.


2y=9%2B3x Add 3x to both sides.


2y=3x%2B9 Rearrange the terms.


y=%283x%2B9%29%2F%282%29 Divide both sides by 2 to isolate y.


y=%283%2F2%29x%2B9%2F2 Break up the fraction.


We can see that the equation y=%283%2F2%29x%2B9%2F2 has a slope m=3%2F2 and a y-intercept b=9%2F2.


Since parallel lines have equal slopes, this means that we know that the slope of the unknown parallel line is m=3%2F2.
Now let's use the point slope formula to find the equation of the parallel line by plugging in the slope m=3%2F2 and the coordinates of the given point .


y-y%5B1%5D=m%28x-x%5B1%5D%29 Start with the point slope formula


y-1=%283%2F2%29%28x--2%29 Plug in m=3%2F2, x%5B1%5D=-2, and y%5B1%5D=1


y-1=%283%2F2%29%28x%2B2%29 Rewrite x--2 as x%2B2


y-1=%283%2F2%29x%2B%283%2F2%29%282%29 Distribute


y-1=%283%2F2%29x%2B3 Multiply


y=%283%2F2%29x%2B3%2B1 Add 1 to both sides.


y=%283%2F2%29x%2B4 Combine like terms.


So the equation of the line parallel to -3x+%2B+2y+=+9 that goes through the point is y=%283%2F2%29x%2B4.


Here's a graph to visually verify our answer:
Graph of the original equation -3x+%2B+2y+=+9 (red) and the parallel line y=%283%2F2%29x%2B4 (green) through the point .


Geometry_Word_Problems/190946: I have a homework problem that I could use some help with-thank you. What is another measure for an angle that measures 283 degrees? _________ degrees.
1 solutions

Answer 143359 by jim_thompson5910(28476) About Me  on 2009-04-13 19:30:32 (Show Source):
You can put this solution on YOUR website!
Just add 360 degrees to the angle to get 283+360=643. So another angle measure is 643 degrees.


Note: adding 360 to an angle makes the angle wrap around one full revolution and come back to the same location as the original angle.


Polynomials-and-rational-expressions/190939: Please help me with this question 3n(squared) + 2n - 1. Thank You
1 solutions

Answer 143354 by jim_thompson5910(28476) About Me  on 2009-04-13 19:11:48 (Show Source):
You can put this solution on YOUR website!
I'm assuming you want to factor?


Looking at the expression 3n%5E2%2B2n-1, we can see that the first coefficient is 3, the second coefficient is 2, and the last term is -1.


Now multiply the first coefficient 3 by the last term -1 to get %283%29%28-1%29=-3.


Now the question is: what two whole numbers multiply to -3 (the previous product) and add to the second coefficient 2?


To find these two numbers, we need to list all of the factors of -3 (the previous product).


Factors of -3:
1,3
-1,-3


Note: list the negative of each factor. This will allow us to find all possible combinations.


These factors pair up and multiply to -3.
1*(-3)
(-1)*(3)

Now let's add up each pair of factors to see if one pair adds to the middle coefficient 2:


First NumberSecond NumberSum
1-31+(-3)=-2
-13-1+3=2



From the table, we can see that the two numbers -1 and 3 add to 2 (the middle coefficient).


So the two numbers -1 and 3 both multiply to -3 and add to 2


Now replace the middle term 2n with -n%2B3n. Remember, -1 and 3 add to 2. So this shows us that -n%2B3n=2n.


3n%5E2%2Bhighlight%28-n%2B3n%29-1 Replace the second term 2n with -n%2B3n.


%283n%5E2-n%29%2B%283n-1%29 Group the terms into two pairs.


n%283n-1%29%2B%283n-1%29 Factor out the GCF n from the first group.


n%283n-1%29%2B1%283n-1%29 Factor out 1 from the second group. The goal of this step is to make the terms in the second parenthesis equal to the terms in the first parenthesis.


%28n%2B1%29%283n-1%29 Combine like terms. Or factor out the common term 3n-1

---------------------------------------------


Answer:


So 3n%5E2%2B2n-1 factors to %28n%2B1%29%283n-1%29.


Note: you can check the answer by FOILing %28n%2B1%29%283n-1%29 to get 3n%5E2%2B2n-1 or by graphing the original expression and the answer (the two graphs should be identical).


Graphs/190927: This question is from textbook saxon algebra 2
4x^3-36x=0
4x(x^2-9)=0
4x(x-3)(x+3)
Is this finished?
1 solutions

Answer 143347 by jim_thompson5910(28476) About Me  on 2009-04-13 18:23:37 (Show Source):
You can put this solution on YOUR website!
You should have 4x%28x-3%29%28x%2B3%29=0. Now set each factor equal to zero:

4x=0, x-3=0, or x%2B3=0


and solve for "x" to get


x=0, x=3 or x=-3


Trigonometry-basics/190819: Can you help me complete this identity?
1)secx - 1/sec x=?

1 solutions

Answer 143336 by jim_thompson5910(28476) About Me  on 2009-04-13 16:14:45 (Show Source):
You can put this solution on YOUR website!
... Start with the given expression


... Replace each secant with 1%2Fcos%28x%29


Multiply the second fraction by the reciprocal


... Multiply the second term by cos%28x%29%2Fcos%28x%29


Multiply


Subtract the fractions


Replace with



So



Note: you can rewrite as and then rewrite as (using the identity tan%28x%29=sin%28x%29%2Fcos%28x%29)


So this also means that


expressions/190842: This question is from textbook Intermediate Algebra an Applied Approach
We are working on logarithms. This was added to our prefinal homework. I am so confused at this point.

Given F(x) = 3x-2, evaluate the following.
a. F(-4)
b. F(-1)
c. F(0)
Here is what i've done so far after several attempts I keep doing it different and confusing myself. I need to understand as finals are next week. Thank you for any help.
f(F,x)=3^(x-2),F(-4)
Evaluate F(-4) by replacing x with -4 in the function.
F(-4)=3^((-4)-2)
F(-4)=(1)/(729)

((1)/(729))

1 solutions

Answer 143332 by jim_thompson5910(28476) About Me  on 2009-04-13 16:00:22 (Show Source):
You can put this solution on YOUR website!
Is the function f%28x%29=3%5E%28x-2%29 ???

Evaluating f(-4):


f%28x%29=3%5E%28x-2%29 Start with the given function


f%28-4%29=3%5E%28-4-2%29 Plug in x=-4


f%28-4%29=3%5E%28-6%29 Subtract


f%28-4%29=1%2F3%5E6 Rewrite the right side with a positive exponent by writing the reciprocal of the base.



f%28-4%29=1%2F729 Raise 3 to the 6th power to get 729


----------------------------


Evaluating f(-1):

f%28x%29=3%5E%28x-2%29 Start with the given function


f%28-1%29=3%5E%28-1-2%29 Plug in x=-1


f%28-1%29=3%5E%28-3%29 Subtract


f%28-1%29=1%2F3%5E3 Rewrite the right side with a positive exponent by writing the reciprocal of the base.


f%28-1%29=1%2F27 Raise 3 to the 3rd power to get 27


----------------------------

Evaluating f(0):

f%28x%29=3%5E%28x-2%29 Start with the given function


f%280%29=3%5E%280-2%29 Plug in x=0


f%280%29=3%5E%28-2%29 Subtract


f%280%29=1%2F3%5E2 Rewrite the right side with a positive exponent by writing the reciprocal of the base.



f%280%29=1%2F9 Square 3 to get 9


----------------------------




Square-cubic-other-roots/190860: Can you please help me solve this? I have to rationalize (the square root of 5) over (the square root of 5)-(1)
1 solutions

Answer 143324 by jim_thompson5910(28476) About Me  on 2009-04-13 15:44:35 (Show Source):
You can put this solution on YOUR website!
%28sqrt%285%29%29%2F%28sqrt%285%29-1%29 Start with the given expression


%28sqrt%285%29%28sqrt%285%29%2B1%29%29%2F%28%28sqrt%285%29-1%29%28sqrt%285%29%2B1%29%29 Multiply both the numerator and the denominator by sqrt%285%29%2B1


%28sqrt%285%29%28sqrt%285%29%2B1%29%29%2F%28%28sqrt%285%29%29%5E2-%281%29%5E2%29 FOIL the denominator using the difference of squares formula


%28sqrt%285%29%28sqrt%285%29%2B1%29%29%2F%285-1%29 Square each term


%28sqrt%285%29%28sqrt%285%29%2B1%29%29%2F%284%29 Combine like terms.


%28sqrt%285%29%2Asqrt%285%29%2B1%2Asqrt%285%29%29%2F%284%29 Distribute


%285%2Bsqrt%285%29%29%2F%284%29 Multiply


So %28sqrt%285%29%29%2F%28sqrt%285%29-1%29=%285%2Bsqrt%285%29%29%2F%284%29


absolute-value/190867: Homework - absolute value
abs(x^2-3) = 2x
I know in absolute value you work it twice once + then -, but im not sure what to do with this one. Thanks
1 solutions

Answer 143321 by jim_thompson5910(28476) About Me  on 2009-04-13 15:39:29 (Show Source):
You can put this solution on YOUR website!
If you have the equation abs%28x%29=a, to find "x", you simply solve the two equations x=a or -x=a


So in this case, to solve abs%28x%5E2-3%29+=+2x, you'll need to solve x%5E2-3=2x (you'll get two solutions here) and you'll need to solve -%28x%5E2-3%29=2x (you'll get two more solutions here)


Once you have the four possible solutions, you need to check them. If any possible solutions do not satisfy the original equation abs%28x%5E2-3%29+=+2x, then they are not a solution.


Let me know if this makes sense. If not, then repost or email me.


Polynomials-and-rational-expressions/190873: Factor by grouping
25x^4-15x^2+10x^2-6
1 solutions

Answer 143315 by jim_thompson5910(28476) About Me  on 2009-04-13 15:24:15 (Show Source):
You can put this solution on YOUR website!
25x%5E4-15x%5E2%2B10x%5E2-6 Start with the given expression


%2825x%5E4-15x%5E2%29%2B%2810x%5E2-6%29 Group like terms


5x%5E2%285x%5E2-3%29%2B%2810x%5E2-6%29 Factor the GCF from the first group


5x%5E2%285x%5E2-3%29%2B2%285x%5E2-3%29 Factor the GCF from the second group


%285x%5E2%2B2%29%285x%5E2-3%29 Combine like terms.


So 25x%5E4-15x%5E2%2B10x%5E2-6 factors to %285x%5E2%2B2%29%285x%5E2-3%29