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Functions/214736: I have to find the composition of functions! Can't figure this one out either!
g(x)=3/(x-1) f(x)=(x-1)/(x-3) find (fog)(x)

Again, thanks!!!!!
1 solutions

Answer 162174 by jim_thompson5910(28598) About Me  on 2009-09-18 18:07:38 (Show Source):
You can put this solution on YOUR website!
Remember that is another way of saying f%28g%28x%29%29.



f%28x%29=%28x-1%29%2F%28x-3%29 Start with the given function.


f%28g%28x%29%29=%283%2F%28x-1%29-1%29%2F%283%2F%28x-1%29-3%29 Plug in g%28x%29=3%2F%28x-1%29


Note: this involves replacing 'x' on the left side with g%28x%29 and replacing each 'x' on the right side with 3%2F%28x-1%29.


Multiply EVERY term by the inner LCD x-1 to clear out the inner fractions.


f%28g%28x%29%29=%283-%28x-1%29%29%2F%283-3%28x-1%29%29 Simplify


f%28g%28x%29%29=%283-x%2B1%29%2F%283-3x%2B3%29 Distribute


f%28g%28x%29%29=%28-x%2B4%29%2F%28-3x%2B6%29 Combine like terms.



So


Linear_Equations_And_Systems_Word_Problems/214725: This question is from textbook Practicing to Take the GRE General Test
I am having problems with this word problem:
A group can charter a particular aircraft at a total fixed cost. If 36 people charter the aircraft rather than 40 people, then the cost per person is greater by $12. What is the cost per person if 40 people charter the aircraft?
I have defined the cost if 40 people charter as x and the cost if 36 people charter as y.
The only equation I can come up with so far is 36y=40(x+12), but I know I need some other equation if I want to solve for either variable.
The back of the book states the answer as 108, but I cannot figure out how to get there.
Thanks in advance for your help!
1 solutions

Answer 162168 by jim_thompson5910(28598) About Me  on 2009-09-18 17:38:19 (Show Source):
You can put this solution on YOUR website!
Let

x=cost per person (for 40 people) in dollars
y=total cost in dollars


If 40 people attend, then the cost per person 'x' is simply the total cost 'y' divided by the number of people going (40). In other words, x=y%2F40 (eg: if the total cost is $80, then the cost per person is 80%2F40=2 dollars). This is your first equation.


Now if 36 people attend instead of 40, the cost per person will increase by $12. So this means that the new cost per person is x%2B12 if 36 people go. This is equal to y%2F36 (since the total cost is now divided among 36 people). So x%2B12=y%2F36. This is the second equation.


x%2B12=y%2F36 Start with the second equation.


y%2F40%2B12=y%2F36 Plug in x=y%2F40


360%28y%2Fcross%2840%29%29%2B360%2812%29=360%28y%2Fcross%2836%29%29 Multiply EVERY term by the LCD 360 to clear out the fractions.


9y%2B4320=10y Multiply and simplify.


9y=10y-4320 Subtract 4320 from both sides.


9y-10y=-4320 Subtract 10y from both sides.


-y=-4320 Combine like terms on the left side.


y=%28-4320%29%2F%28-1%29 Divide both sides by -1 to isolate y.


y=4320 Reduce.


Since 'y' is the total cost, this means that the total cost is $4,320


x=y%2F40 Move back to the first equation.


x=4320%2F40 Plug in y=4320


x=108 Divide


Since 'x' is the cost per person when 40 people were going, this means that the cost per person for 40 people is $108.


Linear-systems/214712: use the intercepts to graph the equation 4x-2y=8 please help me solve and graph
1 solutions

Answer 162150 by jim_thompson5910(28598) About Me  on 2009-09-18 16:38:34 (Show Source):
You can put this solution on YOUR website!

x-intercept


To find the x-intercept, plug in y=0 and solve for x


4x-2y=8 Start with the given equation.


4x-2%280%29=8 Plug in y=0.


4x-0=8 Multiply -2 and 0 to get 0.


4x=8 Simplify.


x=%288%29%2F%284%29 Divide both sides by 4 to isolate x.


x=2 Reduce.


So the x-intercept is .


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


y-intercept


To find the y-intercept, plug in x=0 and solve for y


4x-2y=8 Start with the given equation.


4%280%29-2y=8 Plug in x=0.


0-2y=8 Multiply 4 and 0 to get 0.


-2y=8 Simplify.


y=%288%29%2F%28-2%29 Divide both sides by -2 to isolate y.


y=-4 Reduce.


So the y-intercept is .

Now plot the points




and draw a straight line through them to graph the equation 4x-2y=8


Graph of 4x-2y=8


Inequalities/214692: Solve the inequality, and express the solutions in terms of intervals whenever possible: 3x - 2 > 18

1 solutions

Answer 162126 by jim_thompson5910(28598) About Me  on 2009-09-18 14:00:27 (Show Source):
You can put this solution on YOUR website!
3x+-+2+%3E+18 Start with the given inequality.


3x%3E+18%2B2 Add 2 to both sides.


3x%3E+20 Add


x%3E+20%2F3 Divide both sides by 3 to isolate 'x'


So the solution is x%3E+20%2F3 which in interval notation is


Graphs/214690: Give the center and radius of the circle:
x^2+y^2-10x+6y+25
I first completed the square:
(x^2-10x+25)+(y^2+6y+9)=-25
(x-5)^2+(y-3)^2=-25+25+9
(x-5)+(x-3)=9
(-5,-3) with a radius of 9 but I am not sure if I did that right?!?!
1 solutions

Answer 162125 by jim_thompson5910(28598) About Me  on 2009-09-18 13:55:32 (Show Source):
You can put this solution on YOUR website!
The last equation should be %28x-5%29%5E2%2B%28y%2B3%29%5E2=9, since y%5E2%2B6y%2B9 factors to %28y%2B3%29%5E2. We can take this equation and then rewrite 9 as 3%5E2 and y%2B3 to y-%28-3%29 to get %28x-5%29%5E2%2B%28y-%28-3%29%29%5E2=3%5E2


Recall that the general equation of a circle is %28x-h%29%5E2%2B%28y-k%29%5E2=r%5E2 where (h,k) is the center and 'r' is the radius.


Looking at %28x-5%29%5E2%2B%28y-%28-3%29%29%5E2=3%5E2 (which is in the circle form described above), we see that h=5, k=-3 and r=3 (I'm just matching the two forms).


So the center is (5,-3) and the radius is 3 units.


So you just had some minor errors (such as the sign differences and forgetting to take the square root of 9)


Exponents/214688: write each expression using positive exponets. 7^-2
1 solutions

Answer 162124 by jim_thompson5910(28598) About Me  on 2009-09-18 13:51:27 (Show Source):
You can put this solution on YOUR website!
Recall that x%5E%28-2%29=1%2Fx%5E2. In other words, if you have a negative exponent, you can rewrite the expression with a positive exponent by flipping the fraction.


In this problem, 7%5E%28-2%29=1%2F7%5E2=1%2F49 or simply 7%5E%28-2%29=1%2F49


Expressions-with-variables/214209: Write an algebraic expression for, "four times the sum of 2a and (b) increased by twice the sum of 6a and 2b." Then simplify, indicating the properties used.
1 solutions

Answer 162123 by jim_thompson5910(28598) About Me  on 2009-09-18 13:34:10 (Show Source):
You can put this solution on YOUR website!
"four times the sum of 2a and (b)" translates to 4%282a%2Bb%29

"twice the sum of 6a and 2b" means that 2%286a%2B2b%29

and altogether, "four times the sum of 2a and (b) increased by twice the sum of 6a and 2b." tells us 4%282a%2Bb%29%2B2%286a%2B2b%29


4%282a%2Bb%29%2B2%286a%2B2b%29 Start with the given expression


8a%2B4b%2B12a%2B4b Distribute


20a%2B8b Combine like terms.


So 4%282a%2Bb%29%2B2%286a%2B2b%29=20a%2B8b


Linear-equations/214676: media services charges $20 for a phone and $30/month for its economy plan. What is the total cost of C (t) of operating a media service phone for t months?
C(t)=
what is the total cost for 7 months of service?
C(t)=
1 solutions

Answer 162122 by jim_thompson5910(28598) About Me  on 2009-09-18 13:27:08 (Show Source):
You can put this solution on YOUR website!
Any linear function can be written in the form

f%28t%29=mt%2Bb where 'm' is the slope and represents the change of the function and 'b' is the initial value of the function.


In our case, the change is $30 (since the total cost goes up $30 a month) while the initial fee is $20. So this means m=30 and b=20 giving us the function C%28t%29=30t%2B20


If you're unsure of the answer, simply plug in values of 't'


Examples: When t=0, the number of months is zero. So this represents the start of the plan. Plug this into C(t) to get C%280%29=30%280%29%2B20=20. So no matter what, you're going to pay $20 up front (which is exactly what the problem states).

Now one month later, the value of 't' is now t=1. If you simply add $30 to the down payment of $20, you get $50. In other words, you've paid $50 for the first month. If we plug in t=1, we get C%281%29=30%281%29%2B20=30%2B20=50 which is exactly what we just got.


So you may be asking why we're going through all the trouble of using functions when we could just add. Using functions will save us time for larger values of 't'. For instance, let's say you want to know what the total cost will be 20 months from now. Are you going to add 20 sets of $30 to 20 to find the answer? You could, but why do that when you can simply use the function. Also, you can also answer other questions that the previous technique would have a hard time doing so.

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


To find the cost of 7 months of service, just plug in t=7:


C%28t%29=30t%2B20 Start with the given function.


C%287%29=30%287%29%2B20 Plug in t=7


C%287%29=210%2B20 Multiply


C%287%29=230 Add


So 7 months of service will cost $230


Probability-and-statistics/214683: if a jar contains 23 red marbles and 4 green marbles, the probability that a marble selectted from the jar at random will be green is?
If the above green is not replaced, what is the probability that the next pulled marbles is red?
if you reached into the jar 4 times, what is the probability that you would never choose a green marble (after each pullout you do not replace the chosen marble?
1 solutions

Answer 162121 by jim_thompson5910(28598) About Me  on 2009-09-18 13:18:02 (Show Source):
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a)
Total number of marbles = 23 + 4 = 27 marbles


P(Green Marble) = (# of green marbles)/(# of marbles total) = 4/27 = 0.148


So the probability is 4/27 which is about a 14.8% chance

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

b)

Since the selected marble from part a) is not replaced, the total number of marbles is now 27-1=26

P(Red Marble) = (# of red marbles)/(# of marbles total) = 23/26 = 0.885


So the probability is 23/27 which is about a 88.5% chance

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

c)

To find the probability of NOT choosing green after four selections, you simply calculate the probability of choosing red 4 times in a row (without replacement). This works because there are only two choices in marble selection.


So the basic outline is

P(4 red) = P(red)*P(red with 1 less from total)*P(red with 2 less from total)*P(red with 3 less from total)


I'll let you take it from here. Let me know if you still need help.


Probability-and-statistics/214681: if a jar contains 23 red marbles and 4 green marbles, the probability that a marble selected from the jar at random will be green is?
1 solutions

Answer 162119 by jim_thompson5910(28598) About Me  on 2009-09-18 13:10:46 (Show Source):
You can put this solution on YOUR website!
Total number of marbles = 23 + 4 = 27 marbles


P(Green Marble) = (# of green marbles)/(# of marbles total) = 4/27 = 0.148


So the probability is 4/27 which is about a 14.8% chance


Polynomials-and-rational-expressions/214677: please help me solve this questionfind all numbers for which the rational expression is undefined 8/w-1
1 solutions

Answer 162118 by jim_thompson5910(28598) About Me  on 2009-09-18 13:08:31 (Show Source):
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Is the expression 8%2F%28w-1%29 or is it 8%2Fw-1 ???



8%2F%28w-1%29 is undefined when the denominator w-1 is zero. So set the denominator equal to zero and solve for 'w' to get w-1=0 ----> w=1


So 8%2F%28w-1%29 is undefined when w=1


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


8%2Fw-1 is undefined when the denominator w is zero. So set the denominator equal to zero to get w=0


So 8%2Fw-1 is undefined when w=0


Equations/214537: Please help me solve the following question
5/2t - t = 3 + 3/2t
1 solutions

Answer 162043 by jim_thompson5910(28598) About Me  on 2009-09-17 19:55:32 (Show Source):
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%285%2F2%29t-t=3%2B%283%2F2%29t Start with the given equation.


2%28%285%2Fcross%282%29%29t-t%29=2%283%2B%283%2Fcross%282%29%29t%29 Multiply both sides by the LCD 2 to clear any fractions.


5t-2t=6%2B3t Distribute and multiply.


3t=6%2B3t Combine like terms on the left side.


3t-3t=6 Subtract 3t from both sides.


0t=6 Combine like terms on the left side.


0=6 Simplify.


Since this equation is NEVER true for any 't' value, this means that there are no solutions.


Polynomials-and-rational-expressions/214534: This question is from textbook blitzer college algebra essential
factor x^2+2x-3
1 solutions

Answer 162042 by jim_thompson5910(28598) About Me  on 2009-09-17 19:45:25 (Show Source):
You can put this solution on YOUR website!


Jump to Answer


Looking at the expression x%5E2%2B2x-3, we can see that the first coefficient is 1, the second coefficient is 2, and the last term is -3.


Now multiply the first coefficient 1 by the last term -3 to get %281%29%28-3%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) = -3
(-1)*(3) = -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 2x with -x%2B3x. Remember, -1 and 3 add to 2. So this shows us that -x%2B3x=2x.


x%5E2%2Bhighlight%28-x%2B3x%29-3 Replace the second term 2x with -x%2B3x.


%28x%5E2-x%29%2B%283x-3%29 Group the terms into two pairs.


x%28x-1%29%2B%283x-3%29 Factor out the GCF x from the first group.


x%28x-1%29%2B3%28x-1%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.


%28x%2B3%29%28x-1%29 Combine like terms. Or factor out the common term x-1


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



Answer:


So x%5E2%2B2x-3 factors to %28x%2B3%29%28x-1%29.


In other words, x%5E2%2B2x-3=%28x%2B3%29%28x-1%29.


Note: you can check the answer by expanding %28x%2B3%29%28x-1%29 to get x%5E2%2B2x-3 or by graphing the original expression and the answer (the two graphs should be identical).

Jump to Top


Equations/214498: What is the charge of an ion with 38 electrons, 38 neutrons, and 35 protons?
1 solutions

Answer 162021 by jim_thompson5910(28598) About Me  on 2009-09-17 18:58:11 (Show Source):
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This is more a chemistry question, but I happen to know a little bit about it. Remember that an ion is simply "an atom or molecule where the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge." (from Wikipedia).


Recall that the charge of an electron is -1 while the charge of a single proton is +1. If there are more protons than electrons, then the atom/molecule is positively charged which makes it a cation. If there are more electrons than protons, then the atom/molecule is negatively charged which makes it an anion.


To find the net charge, simply subtract the number of electrons from the number of protons to get: 35-38 = -3


Note: this is the same as saying: 38(1)+35(-1) = -3


So the net charge of this ion is -3 which means that it's negatively charged and that it's an anion.


Rational-functions/214421: Evaluate the following piecewise defined function at f(0), f(2), and f(3)
f(x)= 5 if x<2
2x-3 if x>=2
1 solutions

Answer 161959 by jim_thompson5910(28598) About Me  on 2009-09-17 13:47:58 (Show Source):
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Take note that x=0 satisfies the inequality x%3C2. So to find f%280%29, plug x=0 into the first function f%28x%29=5.


The values x=2 and x=3 are both greater than or equal to 2. So they satisfy x%3E=2. This means to find f(2) and f(3), just plug in x=2 and x=3 respectively into f%28x%29=2x-3.


absolute-value/214420: |-2|
1 solutions

Answer 161957 by jim_thompson5910(28598) About Me  on 2009-09-17 13:33:20 (Show Source):
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abs%28-2%29=2


Remember, the absolute value of ANY number is ALWAYS positive.


Polynomials-and-rational-expressions/214414: how to factor 16x^4-1
1 solutions

Answer 161954 by jim_thompson5910(28598) About Me  on 2009-09-17 13:21:58 (Show Source):
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16x%5E4-1 Start with the given expression.


%284x%5E2%29%5E2-1 Rewrite 16x%5E4 as %284x%5E2%29%5E2.


%284x%5E2%29%5E2-%281%29%5E2 Rewrite 1 as %281%29%5E2


Take note that we have a difference of squares A%5E2-B%5E2 in which A=4x%5E2 and B=1. We can factor this difference of squares using the formula A%5E2-B%5E2=%28A-B%29%28A%2BB%29


A%5E2-B%5E2=%28A-B%29%28A%2BB%29 Start with the difference of squares formula


%284x%5E2%29%5E2-%281%29%5E2=%284x%5E2-1%29%284x%5E2%2B1%29 Plug in A=4x%5E2 and B=1


So 16x%5E4-1 factors to %284x%5E2-1%29%284x%5E2%2B1%29


We can keep going and factor 4x%5E2-1 further.


4x%5E2-1


%282x%29%5E2-%281%29%5E2 Rewrite 4x%5E2 as %282x%29%5E2. Rewrite 1 as %281%29%5E2

Notice that we again have a difference of squares A%5E2-B%5E2 in which A=2x and B=1. We can factor this difference of squares using the formula A%5E2-B%5E2=%28A-B%29%28A%2BB%29


A%5E2-B%5E2=%28A-B%29%28A%2BB%29 Start with the difference of squares formula


%282x%29%5E2-%281%29%5E2=%282x-1%29%282x%2B1%29 Plug in A=2x and B=1


So 4x%5E2-1 factors to %282x-1%29%282x%2B1%29


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

Answer:

Putting all of this together tells us that 16x%5E4-1 completely factors to %282x-1%29%282x%2B1%29%284x%5E2%2B1%29


Equations/214415: 6x+7=25
solve for x
1 solutions

Answer 161952 by jim_thompson5910(28598) About Me  on 2009-09-17 13:15:52 (Show Source):
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6x%2B7=25 Start with the given equation


6x=25-7 Subtract 7 from both sides.


6x=18 Combine like terms.


x=18%2F6 Divide both sides by 6 to isolate 'x'


x=3 Reduce


So the solution is x=3


Divisibility_and_Prime_Numbers/214411: This question is from textbook algebra 1 an integrated approach
if a is an integer, which of the following is always an odd integer?

(a)4a+2 (b)10a (c)8a+1 (d).83
please help!!!!!!
1 solutions

Answer 161951 by jim_thompson5910(28598) About Me  on 2009-09-17 13:09:51 (Show Source):
You can put this solution on YOUR website!
Recall that if 'k' is an integer, then 2k%2B1 is ALWAYS odd. Why? The number 2k is ALWAYS even (because all even integers are a multiple of 2). If you add 1 to an even integer, you will get an odd integer. So this shows us that 2k%2B1 is ALWAYS odd where 'k' is an integer.


So the goal is to try to transform each choice into either the form 2k (even form) or 2k%2B1 (odd form).


a)

4a%2B2 Start with the given expression


2%28a%2B1%29 Factor out the GCF 2


2k Replace 'a+1' with 'k' (which is an integer)


So 4a%2B2 is ALWAYS even (try plugging in some integers for 'a' to test this).

-----------------------------
b)

We can rewrite 10a as 2%2A5a which can come to 2k (where k=5a. So 10a is ALWAYS even.

-----------------------------
c)

We can rewrite 8a%2B1 as 2%2A4a%2B1 and then let k=4a. Now replace '4a' with 'k' to get 2k%2B1. So 8a%2B1=2k%2B1 (where k=4a)

This shows us that 8a%2B1 is ALWAYS odd.

-----------------------------
d)

The value 0.83 is neither even nor odd. Why is this? A number can only be even or odd when it is a whole number or integer. Since 0.83 is NOT a whole number, it is neither even nor odd.



So to recap, the only odd integer of the group is 8a%2B1


Polynomials-and-rational-expressions/214181: Need help in this problem?
Is (-2,-2) a solution of the system
x-3y=4
3x+y=-8
1 solutions

Answer 161766 by jim_thompson5910(28598) About Me  on 2009-09-16 15:36:06 (Show Source):
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Simply plug in x=-2 and y=-2 into both equations and simplify. If you get two identities, then (-2,-2) is the solution. If one is not (or both aren't) an identity, then (-2,-2) is NOT the solution.


Note: an identity is an equation that is ALWAYS true. A simple identity is 0=0.


Polynomials-and-rational-expressions/214178: How is this algebra problem done?
factor p^2+12p+36
1 solutions

Answer 161764 by jim_thompson5910(28598) About Me  on 2009-09-16 15:33:54 (Show Source):
You can put this solution on YOUR website!

Looking at the expression p%5E2%2B12p%2B36, we can see that the first coefficient is 1, the second coefficient is 12, and the last term is 36.


Now multiply the first coefficient 1 by the last term 36 to get %281%29%2836%29=36.


Now the question is: what two whole numbers multiply to 36 (the previous product) and add to the second coefficient 12?


To find these two numbers, we need to list all of the factors of 36 (the previous product).


Factors of 36:
1,2,3,4,6,9,12,18,36
-1,-2,-3,-4,-6,-9,-12,-18,-36


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


These factors pair up and multiply to 36.
1*36
2*18
3*12
4*9
6*6
(-1)*(-36)
(-2)*(-18)
(-3)*(-12)
(-4)*(-9)
(-6)*(-6)

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


First NumberSecond NumberSum
1361+36=37
2182+18=20
3123+12=15
494+9=13
666+6=12
-1-36-1+(-36)=-37
-2-18-2+(-18)=-20
-3-12-3+(-12)=-15
-4-9-4+(-9)=-13
-6-6-6+(-6)=-12



From the table, we can see that the two numbers 6 and 6 add to 12 (the middle coefficient).


So the two numbers 6 and 6 both multiply to 36 and add to 12


Now replace the middle term 12p with 6p%2B6p. Remember, 6 and 6 add to 12. So this shows us that 6p%2B6p=12p.


p%5E2%2Bhighlight%286p%2B6p%29%2B36 Replace the second term 12p with 6p%2B6p.


%28p%5E2%2B6p%29%2B%286p%2B36%29 Group the terms into two pairs.


p%28p%2B6%29%2B%286p%2B36%29 Factor out the GCF p from the first group.


p%28p%2B6%29%2B6%28p%2B6%29 Factor out 6 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.


%28p%2B6%29%28p%2B6%29 Combine like terms. Or factor out the common term p%2B6


%28p%2B6%29%5E2 Condense

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


Answer:


So p%5E2%2B12p%2B36 factors to %28p%2B6%29%5E2.


Note: you can check the answer by FOILing %28p%2B6%29%5E2 to get p%5E2%2B12p%2B36 or by graphing the original expression and the answer (the two graphs should be identical).


Polynomials-and-rational-expressions/214177: How do I solve this algebra problem?
solve x(x-8)= -15
1 solutions

Answer 161763 by jim_thompson5910(28598) About Me  on 2009-09-16 15:32:48 (Show Source):
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x%28x-8%29=+-15 Start with the given equation


x%5E2-8x=+-15 Distribute


x%5E2-8x%2B15=0 Add 15 to both sides.


Notice we have a quadratic in the form of ax%5E2%2Bbx%2Bc where a=1, b=-8, and c=15


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-%28-8%29+%2B-+sqrt%28+%28-8%29%5E2-4%281%29%2815%29+%29%29%2F%282%281%29%29 Plug in a=1, b=-8, and c=15


x+=+%288+%2B-+sqrt%28+%28-8%29%5E2-4%281%29%2815%29+%29%29%2F%282%281%29%29 Negate -8 to get 8.


x+=+%288+%2B-+sqrt%28+64-4%281%29%2815%29+%29%29%2F%282%281%29%29 Square -8 to get 64.


x+=+%288+%2B-+sqrt%28+64-60+%29%29%2F%282%281%29%29 Multiply 4%281%29%2815%29 to get 60


x+=+%288+%2B-+sqrt%28+4+%29%29%2F%282%281%29%29 Subtract 60 from 64 to get 4


x+=+%288+%2B-+sqrt%28+4+%29%29%2F%282%29 Multiply 2 and 1 to get 2.


x+=+%288+%2B-+2%29%2F%282%29 Take the square root of 4 to get 2.


x+=+%288+%2B+2%29%2F%282%29 or x+=+%288+-+2%29%2F%282%29 Break up the expression.


x+=+%2810%29%2F%282%29 or x+=++%286%29%2F%282%29 Combine like terms.


x+=+5 or x+=+3 Simplify.


So the answers are x+=+5 or x+=+3


Exponential-and-logarithmic-functions/214160: I should write this problem in exponential for and simplify.... I know how that works (usually) I just dont get how to do it with this problem;
cubed root of "a" times the fith root of "a".....
3_________________________5
v---- < (the v--- is the sqrt.) times v--- (just ignore the _____)
__a_________________________a
Hope my "doodling" helped a bit.....
1 solutions

Answer 161750 by jim_thompson5910(28598) About Me  on 2009-09-16 15:12:08 (Show Source):
You can put this solution on YOUR website!
root%283%2Ca%29%2Aroot%285%2Ca%29 Start with the given expression


%28a%5E%281%2F3%29%29%2A%28a%5E%281%2F5%29%29%5E%27%27 Convert to exponential notation.


a%5E%281%2F3%2B1%2F5%29%5E%27%27 Use the identity x%5Ey%2Ax%5Ez=x%5E%28y%2Bz%29 to multiply


a%5E%288%2F15%29%5E%27%27 Add the fractions.


root%2815%2Ca%5E8%29 Convert back to radical notation.


So root%283%2Ca%29%2Aroot%285%2Ca%29=root%2815%2Ca%5E8%29


Vectors/214134: Use pythagorean therom to find the distance between (5,3) and(-2,-3).
Can you give me a step by step of this promblem
1 solutions

Answer 161735 by jim_thompson5910(28598) About Me  on 2009-09-16 13:53:38 (Show Source):
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d=sqrt%28%28x%5B1%5D-x%5B2%5D%29%5E2%2B%28y%5B1%5D-y%5B2%5D%29%5E2%29 Start with the distance formula.


d=sqrt%28%285--2%29%5E2%2B%283--3%29%5E2%29 Plug in x%5B1%5D=5, x%5B2%5D=-2, y%5B1%5D=3, and y%5B2%5D=-3.


d=sqrt%28%287%29%5E2%2B%283--3%29%5E2%29 Subtract -2 from 5 to get 7.


d=sqrt%28%287%29%5E2%2B%286%29%5E2%29 Subtract -3 from 3 to get 6.


d=sqrt%2849%2B%286%29%5E2%29 Square 7 to get 49.


d=sqrt%2849%2B36%29 Square 6 to get 36.


d=sqrt%2885%29 Add 49 to 36 to get 85.


So our answer is d=sqrt%2885%29


Which approximates to d=9.22


So the distance between the two points is approximately 9.22 units.


Percentage-and-ratio-word-problems/214133: Two numbers are in the ratio 3: 8.
Their sum is 44.
What is the difference between the two numbers?
1 solutions

Answer 161733 by jim_thompson5910(28598) About Me  on 2009-09-16 13:48:28 (Show Source):
You can put this solution on YOUR website!
Since "Two numbers are in the ratio 3: 8", this means x%2Fy=3%2F8. Also, because "Their sum is 44", we know that x%2By=44. So simply solve this system of equations to find 'x' and 'y'. Let me know if this is enough to get you started.


Distributive-associative-commutative-properties/214131: what is (3a+b)(2a-5b)
1 solutions

Answer 161731 by jim_thompson5910(28598) About Me  on 2009-09-16 13:42:10 (Show Source):
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%283a%2Bb%29%282a-5b%29 Start with the given expression.


Now let's FOIL the expression.


Remember, when you FOIL an expression, you follow this procedure:


%28highlight%283a%29%2Bb%29%28highlight%282a%29-5b%29 Multiply the First terms:%283%2Aa%29%2A%282%2Aa%29=6%2Aa%5E2.


%28highlight%283a%29%2Bb%29%282a%2Bhighlight%28-5b%29%29 Multiply the Outer terms:%283%2Aa%29%2A%28-5%2Ab%29=-15%2Aa%2Ab.


%283a%2Bhighlight%28b%29%29%28highlight%282a%29-5b%29 Multiply the Inner terms:%28b%29%2A%282%2Aa%29=2%2Aa%2Ab.


%283a%2Bhighlight%28b%29%29%282a%2Bhighlight%28-5b%29%29 Multiply the Last terms:%28b%29%2A%28-5%2Ab%29=-5%2Ab%5E2.


6%2Aa%5E2-15%2Aa%2Ab%2B2%2Aa%2Ab-5%2Ab%5E2 Now collect every term to make a single expression.


6%2Aa%5E2-13%2Aa%2Ab-5%2Ab%5E2 Now combine like terms.


So %283a%2Bb%29%282a-5b%29 FOILs to 6%2Aa%5E2-13%2Aa%2Ab-5%2Ab%5E2.


In other words, %283a%2Bb%29%282a-5b%29=6%2Aa%5E2-13%2Aa%2Ab-5%2Ab%5E2.


Quadratic_Equations/214129: +-2x%5E2%2B50=0+
1 solutions

Answer 161729 by jim_thompson5910(28598) About Me  on 2009-09-16 13:40:29 (Show Source):
You can put this solution on YOUR website!

-2x%5E2%2B50=0 Start with the given equation.


Notice we have a quadratic in the form of ax%5E2%2Bbx%2Bc where a=-2, b=0, and c=50


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+=+%280+%2B-+sqrt%28+%280%29%5E2-4%28-2%29%2850%29+%29%29%2F%282%28-2%29%29 Plug in a=-2, b=0, and c=50


x+=+%280+%2B-+sqrt%28+0-4%28-2%29%2850%29+%29%29%2F%282%28-2%29%29 Square 0 to get 0.


x+=+%280+%2B-+sqrt%28+0--400+%29%29%2F%282%28-2%29%29 Multiply 4%28-2%29%2850%29 to get -400


x+=+%280+%2B-+sqrt%28+0%2B400+%29%29%2F%282%28-2%29%29 Rewrite sqrt%280--400%29 as sqrt%280%2B400%29


x+=+%280+%2B-+sqrt%28+400+%29%29%2F%282%28-2%29%29 Add 0 to 400 to get 400


x+=+%280+%2B-+sqrt%28+400+%29%29%2F%28-4%29 Multiply 2 and -2 to get -4.


x+=+%280+%2B-+20%29%2F%28-4%29 Take the square root of 400 to get 20.


x+=+%280+%2B+20%29%2F%28-4%29 or x+=+%280+-+20%29%2F%28-4%29 Break up the expression.


x+=+%2820%29%2F%28-4%29 or x+=++%28-20%29%2F%28-4%29 Combine like terms.


x+=+-5 or x+=+5 Simplify.


So the answers are x+=+-5 or x+=+5


Graphs/214116: How do you graph the relatin (0,0), (2,4), (-4,0), and find the domain and range.It asks you to determine whether the relation is a function or not. I am totally lost. Please help!
Thank you!
This is not from a book. It was a worksheet given to me.
1 solutions

Answer 161726 by jim_thompson5910(28598) About Me  on 2009-09-16 13:17:46 (Show Source):
You can put this solution on YOUR website!
Simply plot the points given. The domain is the set of all x values while the range is the set of all y values of the given points. So we get:

Domain: {0, 2, -4}

Range: {0, 4}


Take note that each value of 'x' only maps to one 'y' value. So this means that the relation is a function.


Equations/214126: My daughter is in 5th grade and learning "Hands on Equations" using manipulatives. I was never very good with algebra so I can't remember any of it and am no help to her. Are you familiar with this technique? Can you show me how to solve x + 2 + 2x = x + 10? This is not from a textbook...just an example for me. Thanks!
1 solutions

Answer 161725 by jim_thompson5910(28598) About Me  on 2009-09-16 13:13:12 (Show Source):
You can put this solution on YOUR website!
x%2B2%2B2x=x%2B10 Start with the given equation.


3x%2B2=x%2B10 Combine like terms on the left side.


3x=x%2B10-2 Subtract 2 from both sides.


3x-x=10-2 Subtract x from both sides.


2x=10-2 Combine like terms on the left side.


2x=8 Combine like terms on the right side.


x=%288%29%2F%282%29 Divide both sides by 2 to isolate x.


x=4 Reduce.


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

Answer:

So the answer is x=4


Radicals/214122: Please help me with find factoring. Thank you
Mutiply and simplify by factoring.
Sqrt(45)*Sqrt(250)
Sqrt(45)*(250)=11250
Sqrt(11250)= factoring will be?

1 solutions

Answer 161724 by jim_thompson5910(28598) About Me  on 2009-09-16 13:12:15 (Show Source):
You can put this solution on YOUR website!
sqrt%2845%29%2Asqrt%28250%29 Start with the given expression.


sqrt%289%2A5%29%2Asqrt%2825%2A10%29 Factor each radicand into a product in which one factor is a perfect square (the largest perfect square factor)


sqrt%289%29%2Asqrt%285%29%2Asqrt%2825%29%2Asqrt%2810%29 Break up the roots.


3%2Asqrt%285%29%2A5%2Asqrt%2810%29 Take the square root of the perfect squares 9 and 25 to get 3 and 5.


3%2A5%2Asqrt%285%2A10%29Recombine the roots.


15%2Asqrt%2850%29 Multiply


15%2Asqrt%2825%2A2%29 Factor 50 into 25*2 (take note how 25 is the largest perfect square that goes into 50)


15%2Asqrt%2825%29%2Asqrt%282%29 Break up the root.


15%2A5%2Asqrt%282%29 Take the square root of 25 to get 5.


75%2Asqrt%282%29 Multiply


So sqrt%2845%29%2Asqrt%28250%29=75%2Asqrt%282%29


Exponential-and-logarithmic-functions/214121: 1. Simplify and write the expression below using positive exponents only.
(2u-3v2)-2

1 solutions

Answer 161723 by jim_thompson5910(28598) About Me  on 2009-09-16 13:06:04 (Show Source):
You can put this solution on YOUR website!
Recall that x%5E%28-1%29=1%2Fx%5E1=1%2Fx and x%5E%28-2%29=1%2Fx%5E2. In other words, to rewrite an expression with positive exponents, just flip the base.


So in this case u%5E%28-3%29=1%2Fu%5E3. So 2u%5E%28-3%29v%5E2=2%281%2Fu%5E3%29v%5E2=%282v%5E2%29%2Fu%5E3


So %282u%5E%28-3%29v%5E2%29%5E%28-2%29=%28%282v%5E2%29%2Fu%5E3%29%5E%28-2%29



Now flip the fraction to make the outer exponent positive: %28%282v%5E2%29%2Fu%5E3%29%5E%28-2%29=%28%28u%5E3%29%2F%282v%5E2%29%29%5E2


Now simplify to get: %28%28u%5E3%29%2F%282v%5E2%29%29%5E2=%28u%5E6%29%2F%284v%5E4%29

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

Answer:

So %282u%5E%28-3%29v%5E2%29%5E%28-2%29=%28u%5E6%29%2F%284v%5E4%29