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Money_Word_Problems/195126: i have the first part of this question solved, i just need help with the second part. thank you.
a company earns a weekly profit of P=-1.2x^2+180x-280, where x is the number of coffee tables they build and sell and P is profit in dollars.
a. find the number of coffee tables the company must sell in a week in order to obtain max. profit.
(i completed the work for this problem and got 75 coffee tables)
b. what is the maximum profit?
(i have the answer key and i tried plugging 75 coffee tables into the equation but i am getting an answer that seems to be way off)
thank you for your help
1 solutions

Answer 146355 by jim_thompson5910(28536) About Me  on 2009-05-06 16:15:26 (Show Source):
You can put this solution on YOUR website!
a) Correct.

b)

P=-1.2x%5E2%2B180x-280 Start with the given equation.


P=-1.2%2875%29%5E2%2B180%2875%29-280 Plug in x=75.


P=-1.2%285625%29%2B180%2875%29-280 Square 75 to get 5625.


P=-6750%2B180%2875%29-280 Multiply -1.2 and 5625 to get -6750.


P=-6750%2B13500-280 Multiply 180 and 75 to get 13500.


P=6470 Combine like terms.


So the max profit is $6,470.


Distributive-associative-commutative-properties/195123: This question is from textbook
I need help with the factoring equation and step by step solution to 3y-21+xy-7
1 solutions

Answer 146354 by jim_thompson5910(28536) About Me  on 2009-05-06 16:11:54 (Show Source):
You can put this solution on YOUR website!
Are you sure that the equation isn't 3y-21%2Bxy-7x ??


3y-21%2Bxy-7x Start with the given expression


%283y-21%29%2B%28xy-7x%29 Group like terms


3%28y-7%29%2Bx%28y-7%29 Factor out the GCF 3 out of the first group. Factor out the GCF x out of the second group


%283%2Bx%29%28y-7%29 Since we have the common term y-7, we can combine like terms


So 3y-21%2Bxy-7x factors to %283%2Bx%29%28y-7%29


Linear-systems/195096: This question is from textbook algebra 1 concepts and skills
3x-2y=11
-x+6y=7
(5,2)
1 solutions

Answer 146336 by jim_thompson5910(28536) About Me  on 2009-05-06 13:37:28 (Show Source):
You can put this solution on YOUR website!

Let's see if x=5 and y=2 are solutions to the first equation.


3x-2y=11 Start with the first equation.


3%2A%285%29-2%2A%282%29=11 Plug in x=5 and y=2.


15-4=11 Multiply


11=11 Combine like terms.


Since the equation is true, this means that (5,2) is a solution to the first equation.


Let's see if (5,2) is a solution to the second equation.


-x%2B6y=7 Start with the second equation.


-%285%29%2B6%2A%282%29=7 Plug in x=5 and y=2.


-5%2B12=7 Multiply


7=7 Combine like terms.


Since the equation is true, this means that (5,2) is also a solution to the second equation.


Since all of the equations of the system are true, this means that (5,2) is a solution to the given system.


Signed-numbers/195102: I have another two questions. This is confusing to me too. please help me.


3.) What value should be added to the expression to create a perfect square?
x2 - 20x



4. Solve.
x2 + 8x 8 = 0

1 solutions

Answer 146334 by jim_thompson5910(28536) About Me  on 2009-05-06 13:32:58 (Show Source):
You can put this solution on YOUR website!
3)

x%5E2-20x Start with the given expression


Now take half of the x coefficient and square it to get %28-20%2F2%29%5E2=%28-10%29%5E2=100. This is the value that you add to the expression to make it a perfect square.

So x%5E2-20x%2B100 is a perfect square.





4)

Is the equation x%5E2%2B8x%2B8=0 ???



x%5E2%2B8x%2B8=0 Start with the given equation.


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


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-%288%29+%2B-+sqrt%28+%288%29%5E2-4%281%29%288%29+%29%29%2F%282%281%29%29 Plug in a=1, b=8, and c=8


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


x+=+%28-8+%2B-+sqrt%28+64-32+%29%29%2F%282%281%29%29 Multiply 4%281%29%288%29 to get 32


x+=+%28-8+%2B-+sqrt%28+32+%29%29%2F%282%281%29%29 Subtract 32 from 64 to get 32


x+=+%28-8+%2B-+sqrt%28+32+%29%29%2F%282%29 Multiply 2 and 1 to get 2.


x+=+%28-8+%2B-+4%2Asqrt%282%29%29%2F%282%29 Simplify the square root


x+=+%28-8%29%2F%282%29+%2B-+%284%2Asqrt%282%29%29%2F%282%29 Break up the fraction.


x+=+-4+%2B-+2%2Asqrt%282%29 Reduce.


x+=+-4%2B2%2Asqrt%282%29 or x+=+-4-2%2Asqrt%282%29 Break up the expression.


So the answers are x+=+-4%2B2%2Asqrt%282%29 or x+=+-4-2%2Asqrt%282%29


which approximate to x=-1.172 or x=-6.828


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

OR....

Is the equation x%5E2%2B8x-8=0 ???




x%5E2%2B8x-8=0 Start with the given equation.


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


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-%288%29+%2B-+sqrt%28+%288%29%5E2-4%281%29%28-8%29+%29%29%2F%282%281%29%29 Plug in a=1, b=8, and c=-8


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


x+=+%28-8+%2B-+sqrt%28+64--32+%29%29%2F%282%281%29%29 Multiply 4%281%29%28-8%29 to get -32


x+=+%28-8+%2B-+sqrt%28+64%2B32+%29%29%2F%282%281%29%29 Rewrite sqrt%2864--32%29 as sqrt%2864%2B32%29


x+=+%28-8+%2B-+sqrt%28+96+%29%29%2F%282%281%29%29 Add 64 to 32 to get 96


x+=+%28-8+%2B-+sqrt%28+96+%29%29%2F%282%29 Multiply 2 and 1 to get 2.


x+=+%28-8+%2B-+4%2Asqrt%286%29%29%2F%282%29 Simplify the square root


x+=+%28-8%29%2F%282%29+%2B-+%284%2Asqrt%286%29%29%2F%282%29 Break up the fraction.


x+=+-4+%2B-+2%2Asqrt%286%29 Reduce.


x+=+-4%2B2%2Asqrt%286%29 or x+=+-4-2%2Asqrt%286%29 Break up the expression.


So the answers are x+=+-4%2B2%2Asqrt%286%29 or x+=+-4-2%2Asqrt%286%29


which approximate to x=0.899 or x=-8.899


Complex_Numbers/195104: Simplify quotient and write answer in a + bi form.
6 + 2i divided by 4-3i
1 solutions

Answer 146328 by jim_thompson5910(28536) About Me  on 2009-05-06 12:58:59 (Show Source):
You can put this solution on YOUR website!
%286%2B2i%29%2F%284-3i%29 Start with the given expression.


%28%286%2B2i%29%2F%284-3i%29%29%28%284%2B3i%29%2F%284%2B3i%29%29 Multiply the fraction by %284%2B3i%29%2F%284%2B3i%29.


%28%286%2B2i%29%284%2B3i%29%29%2F%28%284-3i%29%284%2B3i%29%29 Combine the fractions.


FOIL the numerator.


FOIL the denominator.


%2824%2B18i%2B8i%2B6i%5E2%29%2F%2816%2B12i-12i-9i%5E2%29 Multiply.


%2818%2B26i%29%2F%2825%29 Combine like terms.


18%2F25%2B%2826%2F25%29i Break up the fraction.


So %286%2B2i%29%2F%284-3i%29=18%2F25%2B%2826%2F25%29i.


So the expression is now in standard form a%2Bbi where a=18%2F25 and b=26%2F25


Quadratic_Equations/194983: Solve 6x^2+38x+12=0
1 solutions

Answer 146261 by jim_thompson5910(28536) About Me  on 2009-05-05 19:43:02 (Show Source):
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6x%5E2%2B38x%2B12=0 Start with the given equation.


Notice we have a quadratic equation in the form of ax%5E2%2Bbx%2Bc where a=6, b=38, and c=12


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-%2838%29+%2B-+sqrt%28+%2838%29%5E2-4%286%29%2812%29+%29%29%2F%282%286%29%29 Plug in a=6, b=38, and c=12


x+=+%28-38+%2B-+sqrt%28+1444-4%286%29%2812%29+%29%29%2F%282%286%29%29 Square 38 to get 1444.


x+=+%28-38+%2B-+sqrt%28+1444-288+%29%29%2F%282%286%29%29 Multiply 4%286%29%2812%29 to get 288


x+=+%28-38+%2B-+sqrt%28+1156+%29%29%2F%282%286%29%29 Subtract 288 from 1444 to get 1156


x+=+%28-38+%2B-+sqrt%28+1156+%29%29%2F%2812%29 Multiply 2 and 6 to get 12.


x+=+%28-38+%2B-+34%29%2F%2812%29 Take the square root of 1156 to get 34.


x+=+%28-38+%2B+34%29%2F%2812%29 or x+=+%28-38+-+34%29%2F%2812%29 Break up the expression.


x+=+%28-4%29%2F%2812%29 or x+=++%28-72%29%2F%2812%29 Combine like terms.


x+=+-1%2F3 or x+=+-6 Simplify.


So the answers are x+=+-1%2F3 or x+=+-6



Polynomials-and-rational-expressions/194980: I need help with this factoring problem if you could?????
4s^3+s^6-45=
Thanks for all your help!!!!!
1 solutions

Answer 146259 by jim_thompson5910(28536) About Me  on 2009-05-05 19:40:36 (Show Source):
You can put this solution on YOUR website!
4s%5E3%2Bs%5E6-45 Start with the given expression.


s%5E6%2B4s%5E3-45 Rearrange the terms.


Looking at s%5E6%2B4s%5E3-45 we can see that the first term is s%5E6 and the last term is -45 where the coefficients are 1 and -45 respectively.

Now multiply the first coefficient 1 and the last coefficient -45 to get -45. Now what two numbers multiply to -45 and add to the middle coefficient 4? Let's list all of the factors of -45:



Factors of -45:
1,3,5,9,15,45

-1,-3,-5,-9,-15,-45 ...List the negative factors as well. This will allow us to find all possible combinations

These factors pair up and multiply to -45
(1)*(-45)
(3)*(-15)
(5)*(-9)
(-1)*(45)
(-3)*(15)
(-5)*(9)

note: remember, the product of a negative and a positive number is a negative number


Now which of these pairs add to 4? Lets make a table of all of the pairs of factors we multiplied and see which two numbers add to 4

First NumberSecond NumberSum
1-451+(-45)=-44
3-153+(-15)=-12
5-95+(-9)=-4
-145-1+45=44
-315-3+15=12
-59-5+9=4



From this list we can see that -5 and 9 add up to 4 and multiply to -45


Now looking at the expression s%5E6%2B4s%5E3-45, replace 4s%5E3 with -5s%5E3%2B9s%5E3 (notice -5s%5E3%2B9s%5E3 adds up to 4s%5E3. So it is equivalent to 4s%5E3)

s%5E6%2Bhighlight%28-5s%5E3%2B9s%5E3%29-45


Now let's factor s%5E6-5s%5E3%2B9s%5E3-45 by grouping:


%28s%5E6-5s%5E3%29%2B%289s%5E3-45%29 Group like terms


s%5E3%28s%5E3-5%29%2B9%28s%5E3-5%29 Factor out the GCF of s%5E3 out of the first group. Factor out the GCF of 9 out of the second group


%28s%5E3%2B9%29%28s%5E3-5%29 Since we have a common term of s%5E3-5, we can combine like terms

So s%5E6-5s%5E3%2B9s%5E3-45 factors to %28s%5E3%2B9%29%28s%5E3-5%29


So this also means that s%5E6%2B4s%5E3-45 factors to %28s%5E3%2B9%29%28s%5E3-5%29 (since s%5E6%2B4s%5E3-45 is equivalent to s%5E6-5s%5E3%2B9s%5E3-45)



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



Answer:
So 4s%5E3%2Bs%5E6-45 completely factors to %28s%5E3%2B9%29%28s%5E3-5%29


Polynomials-and-rational-expressions/194979: Hi, could you please help me with factoring?
4s^3+12s^2-64s-192=
I am not sure what I am doing, but I am not coming up with the correct answer.
Thanks
1 solutions

Answer 146258 by jim_thompson5910(28536) About Me  on 2009-05-05 19:38:15 (Show Source):
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4s%5E3%2B12s%5E2-64s-192 Start with the given expression


4%28s%5E3%2B3s%5E2-16s-48%29 Factor out the GCF 4


4%28%28s%5E3%2B3s%5E2%29%2B%28-16s-48%29%29 Group like terms


4%28s%5E2%28s%2B3%29-16%28s%2B3%29%29 Factor out the GCF 4s%5E2 out of the first group. Factor out the GCF -64 out of the second group


4%28%28s%5E2-16%29%28s%2B3%29%29 Since we have the common term s%2B3, we can combine like terms


4%28s-4%29%28s%2B4%29%28s%2B3%29 Factor s%5E2-16 to get %28s-4%29%28s%2B4%29


So 4s%5E3%2B12s%5E2-64s-192 completely factors to 4%28s-4%29%28s%2B4%29%28s%2B3%29


Trigonometry-basics/194974: How do you verify cos(A+B)+cos(A-B)=2cosAcosB
1 solutions

Answer 146251 by jim_thompson5910(28536) About Me  on 2009-05-05 19:05:33 (Show Source):
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I'd start with the left side and work my way to get it equal to the right side (if you go with the left side, do NOT change the right).


Recall the identities:

cos(A+B) = cos(A)cos(B)-sin(A)sin(B), and


cos(A-B) = cos(A)cos(B)+sin(A)sin(B)


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



cos(A+B)+cos(A-B)=2cos(A)cos(B) ... Start with the given equation.


[cos(A)cos(B)-sin(A)sin(B)]+cos(A-B)=2cos(A)cos(B) ... Use the first identity given above


[cos(A)cos(B)-sin(A)sin(B)]+[cos(A)cos(B)+sin(A)sin(B)]=2cos(A)cos(B) ... Use the second identity given above


[cos(A)cos(B)+cos(A)cos(B)]+[-sin(A)sin(B)+sin(A)sin(B)]=2cos(A)cos(B) ... Rearrange the terms.


2cos(A)cos(B)+0=2cos(A)cos(B) ... Combine like terms.


2cos(A)cos(B)=2cos(A)cos(B) ... Simplify


Since both sides are equal, we've verified the identity.


Complex_Numbers/194943: please explain how to simplify...

i to the 100th power
1 solutions

Answer 146249 by jim_thompson5910(28536) About Me  on 2009-05-05 18:56:12 (Show Source):
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Since i=sqrt%28-1%29, this means that


i%5E1=i


i%5E2=%28sqrt%28-1%29%29%5E2=-1 or i%5E2=-1


i%5E3=%28sqrt%28-1%29%29%5E3=%28sqrt%28-1%29%29%5E2%2Asqrt%28-1%29=-1%2Ai=-i or i%5E3=-i


i%5E4=%28sqrt%28-1%29%29%5E4=%28sqrt%28-1%29%29%5E2%2A%28sqrt%28-1%29%29%5E2=-1%2A-1=1 or i%5E4=1


i%5E5=%28sqrt%28-1%29%29%5E5=%28sqrt%28-1%29%29%5E4%2Asqrt%28-1%29=1%2Ai=i or i%5E5=i


etc...

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

So for every increment of the exponent, the powers of "i" are: i, -1, -i, 1, i, etc... and this pattern repeats every 4 terms (notice how the 5th term is identical to the first term).


This pattern can be generalized to the following:

For i%5Ek (where "k" is a whole number),


If the remainder of k%2F4 is 0, then i%5Ek=1.


If the remainder of k%2F4 is 1, then i%5Ek=i.


If the remainder of k%2F4 is 2, then i%5Ek=-1.


If the remainder of k%2F4 is 3, then i%5Ek=-i.


So out at the 100th term, since 100%2F4=25 remainder 0, this means that i%5E%28100%29=1


Rational-functions/194964: What is The simplest form of [3^(1/2)*8^(1/3)]^2
1 solutions

Answer 146245 by jim_thompson5910(28536) About Me  on 2009-05-05 18:42:22 (Show Source):
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... Start with the given expression.



... Multiply the outer exponent by EVERY exponent in the parenthesis.


... Multiply


... Reduce


... Simplify


... Convert to radical notation.


... Take the cube root of 8 to get 2


... Square 2 to get 4


... Multiply



So


Equations/194965: x/4 + 11x/4 = x/20
1 solutions

Answer 146243 by jim_thompson5910(28536) About Me  on 2009-05-05 18:37:59 (Show Source):
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x%2F4%2B11x%2F4=x%2F20 Start with the given equation.


Multiply EVERY term by the LCD 20 to clear any fractions.


5x%2B55x=x Multiply.


60x=x Combine like terms on the left side.


60x-x=0 Subtract x from both sides.


59x=0 Combine like terms on the left side.


x=%280%29%2F%2859%29 Divide both sides by 59 to isolate x.


x=0 Reduce.


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

Answer:

So the answer is x=0


Expressions-with-variables/194960: I NEED HELP TO LEARN HOW TO SIMPLIFY THIS EQUATION
X SQUARED+8X+15 DIVIDED BY X SQUARED +5X+6
1 solutions

Answer 146241 by jim_thompson5910(28536) About Me  on 2009-05-05 18:35:48 (Show Source):
You can put this solution on YOUR website!
Please don't type in all uppercase. It's hard to read that way.



%28x%5E2%2B8x%2B15%29%2F%28x%5E2%2B5x%2B6%29 Start with the given expression.


%28%28x%2B5%29%28x%2B3%29%29%2F%28x%5E2%2B5x%2B6%29 Factor x%5E2%2B8x%2B15 to get %28x%2B5%29%28x%2B3%29.


%28%28x%2B5%29%28x%2B3%29%29%2F%28%28x%2B3%29%28x%2B2%29%29 Factor x%5E2%2B5x%2B6 to get %28x%2B3%29%28x%2B2%29.


%28%28x%2B5%29highlight%28%28x%2B3%29%29%29%2F%28highlight%28%28x%2B3%29%29%28x%2B2%29%29 Highlight the common terms.


%28%28x%2B5%29cross%28%28x%2B3%29%29%29%2F%28cross%28%28x%2B3%29%29%28x%2B2%29%29 Cancel out the common terms.


%28x%2B5%29%2F%28x%2B2%29 Simplify.


So %28x%5E2%2B8x%2B15%29%2F%28x%5E2%2B5x%2B6%29 simplifies to %28x%2B5%29%2F%28x%2B2%29.


In other words, %28x%5E2%2B8x%2B15%29%2F%28x%5E2%2B5x%2B6%29=%28x%2B5%29%2F%28x%2B2%29 where x%3C%3E-3 or x%3C%3E-2


Polynomials-and-rational-expressions/194961: I NEED HELP TO LEARN HOW TO SIMPLIFY THIS EQUATION
X SQUARED+8X+15 DIVIDED BY X SQUARED +5X+6
1 solutions

Answer 146239 by jim_thompson5910(28536) About Me  on 2009-05-05 18:35:09 (Show Source):
You can put this solution on YOUR website!
Please don't type in all uppercase. It's hard to read that way.



%28x%5E2%2B8x%2B15%29%2F%28x%5E2%2B5x%2B6%29 Start with the given expression.


%28%28x%2B5%29%28x%2B3%29%29%2F%28x%5E2%2B5x%2B6%29 Factor x%5E2%2B8x%2B15 to get %28x%2B5%29%28x%2B3%29.


%28%28x%2B5%29%28x%2B3%29%29%2F%28%28x%2B3%29%28x%2B2%29%29 Factor x%5E2%2B5x%2B6 to get %28x%2B3%29%28x%2B2%29.


%28%28x%2B5%29highlight%28%28x%2B3%29%29%29%2F%28highlight%28%28x%2B3%29%29%28x%2B2%29%29 Highlight the common terms.


%28%28x%2B5%29cross%28%28x%2B3%29%29%29%2F%28cross%28%28x%2B3%29%29%28x%2B2%29%29 Cancel out the common terms.


%28x%2B5%29%2F%28x%2B2%29 Simplify.


So %28x%5E2%2B8x%2B15%29%2F%28x%5E2%2B5x%2B6%29 simplifies to %28x%2B5%29%2F%28x%2B2%29.


In other words, %28x%5E2%2B8x%2B15%29%2F%28x%5E2%2B5x%2B6%29=%28x%2B5%29%2F%28x%2B2%29 where x%3C%3E-3 or x%3C%3E-2


Expressions-with-variables/194899: I'm very confused about this problem, so I really hope someone can help me. I dont know how to type this and I looked at the fourmula plotting system but couldnt find anything, so I will try to explain it the best I can.
I have to write an expression for the following.
y+y+...+y
(then there is a curly bracket under it making it look like a fraction(except that its a curly bracket) and under the bracket is the following)
x of them
1 solutions

Answer 146237 by jim_thompson5910(28536) About Me  on 2009-05-05 18:31:35 (Show Source):
You can put this solution on YOUR website!
Let's start off with some simple cases:

Case 1: If we have only one y, then we'll simply have y=1y


Case 2: If we add up two y's, then y%2By=2y


Case 3: If we add up three y's, then y%2By%2By=3y


Case 4: If we add up four y's, then y%2By%2By%2By=4y


etc...


So all we're doing is placing the number of y's that we're adding in front of the y's.


So if we add up 5 y's, then we'll get 5y


If we add up 22 y's, then we'll get 22y.


So if we add up "x" y's, then we'll get xy which is the answer.


Note: the reason why this works is because multiplication is really a shortcut for repeated addition.


Inequalities/194918: This question is from textbook mathematics application and concepts
can you please help me answer this question: -4k+1>-11
1 solutions

Answer 146215 by jim_thompson5910(28536) About Me  on 2009-05-05 15:36:16 (Show Source):
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-4k%2B1%3E-11 Start with the given inequality.


-4k%3E-11-1 Subtract 1 from both sides.


-4k%3E-12 Combine like terms on the right side.


k%3C%28-12%29%2F%28-4%29 Divide both sides by -4 to isolate k. note: Remember, the inequality sign flips when we divide both sides by a negative number.


k%3C3 Reduce.


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

Answer:

So the answer is k%3C3


Exponential-and-logarithmic-functions/194916: Please help me with this problem: ln(4)-ln(x)=10
1 solutions

Answer 146213 by jim_thompson5910(28536) About Me  on 2009-05-05 15:35:20 (Show Source):
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ln%284%29-ln%28x%29=10 Start with the given equation


ln%284%2Fx%29=10 Combine the logs using the identity ln%28x%29-ln%28y%29=ln%28x%2Fy%29


e%5E10=4%2Fx Use the property ln%28x%29=y ----> e%5Ey=x to rewrite the equation.


x%2Ae%5E10=4 Multiply both sides by "x"


x=4%2Fe%5E%2810%29 Divide both sides by e%5E%2810%29


So the solution is x=4%2Fe%5E%2810%29


Probability-and-statistics/194866:
1 solutions

Answer 146186 by jim_thompson5910(28536) About Me  on 2009-05-05 12:02:09 (Show Source):
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# 1

Remember, probability is simply a formal way of representing the chance of an event occurring. Probability is most often represented as a fraction where the numerator is the number of ways that given event can occur over the denominator which represents the total number of possible outcomes.

In other words, this fraction looks like




where the notation "P(Event Occurring)" stands for "the probability of the event occurring"


So whenever you hear something like "the chances of that happening are one out of two", they mean that the event can occur one way out of two possible ways total. So they might be describing a coin toss where the chances of heads is "one out of two" since there's only one way to land on heads out of the two possible sides of the coin.


a)

Let's say that we have a deck of 52 cards and I want to know what the chances are of drawing a blue card. Since there are NO blue cards (there are only red and black cards), this means that the numerator is equal to zero while the denominator is still equal to 52. So this means that the probability of drawing a blue card is:



So the probability of choosing a blue card is 0 which means that there's a 0% chance of choosing a blue card.

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

b)
Let's again say that we have a deck of 52 cards, but this time we want to know the chances of drawing a card (this is trivial, but important). Since there are 52 cards, and there are 52 ways to draw one card, this means that



So the probability of drawing a card is 1. In other words, no matter which card you choose, you're still selecting a card. So there is a 100% certainty that you'll select a card.


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

# 2

The outcomes of an experiment are the results after running the simulation. Whatever experiment you run, the outcomes are the OBSERVED occurrences of an event.

For instance, let's say that you're flipping a coin and you observe the coin lands on: heads, tails, heads, heads, heads, and tails.

The outcomes of the experiment are the results of heads, tails, heads, heads, heads, and tails where the experiment is flipping a coin.

Note: an experiment in this sense is simply a simulation of an event (eg flipping a coin, rolling a die, drawing a card)

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

Here's another example. Now you're rolling a single die and you roll the following: 1, 4, 2, 5, 1, 6, 2, and 3

The numbers 1, 4, 2, 5, 1, 6, 2, and 3 are all outcomes of the experiment of rolling a die.


Note: A more sophisticated experiment would involve more factors (and not be as simple as rolling a die or flipping a coin).


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

When we say that the outcomes are equally likely, we're simply saying that the probability of the outcomes are equal.

Back in the coin flipping example, the chances of landing on heads is 1%2F2 (since there's one way to get heads out of 2 possible outcomes). Likewise, the chances of getting tails is also 1%2F2 (there's one way to get tails out of 2 possible outcomes).

Since P%28heads%29=P%28tails%29, this means that the chances of getting either one is equally likely. So this means that the outcomes are equally likely.


In the die rolling example, the chances of rolling any number from 1 to 6 are 1%2F6 (since for any given number, there's only one way to get that number out of the 6 numbers on the die). Since the chances of getting any number on the die is 1%2F6, these outcomes are also equally likely.


Quadratic_Equations/194753: Please Help. Use the discriminant to determine the number types of solutions of the quadratic equation t^2+8t+20=0.
1 solutions

Answer 146100 by jim_thompson5910(28536) About Me  on 2009-05-04 19:44:20 (Show Source):
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From t%5E2%2B8t%2B20 we can see that a=1, b=8, and c=20


D=b%5E2-4ac Start with the discriminant formula.


D=%288%29%5E2-4%281%29%2820%29 Plug in a=1, b=8, and c=20


D=64-4%281%29%2820%29 Square 8 to get 64


D=64-80 Multiply 4%281%29%2820%29 to get %284%29%2820%29=80


D=-16 Subtract 80 from 64 to get -16


Since the discriminant is less than zero, this means that there are two complex solutions.


In other words, there are no real solutions.


Exponential-and-logarithmic-functions/194745: Condense
6log2x-36 log 2 y
1 solutions

Answer 146094 by jim_thompson5910(28536) About Me  on 2009-05-04 19:11:52 (Show Source):
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6log%282%2C%28x%29%29-36log%282%2C%28y%29%29 Start with the given expression.


log%282%2C%28x%5E6%29%29-log%282%2C%28y%5E%2836%29%29%29 Rewrite the logs using the identity y%2Alog%28b%2C%28x%29%29=log%28b%2C%28x%5Ey%29%29


log%282%2C%28%28x%5E6%29%2F%28y%5E%2836%29%29%29%29 Combine the logs using the identity log%28b%2C%28A%29%29-log%28b%2C%28B%29%29=log%28b%2C%28A%2FB%29%29


So where every variable is positive.


Travel_Word_Problems/194738: The rate of a jet is 400 mph in calm air. Traveling with the wind, the jet can fly 2100 miles in the same amount of time as it takes to fly 1900 miles against the wind. Find the rate of the wind.
d=rt
calm air = 400 mph
distance with wind = 2100 miles
distance against wind = 1900 miles
2100 = (400+w)*?
1900 = (400-w)*?
I understand that we need to find w(rate of wind), but what's the time? The problem just states that it is the same.
1 solutions

Answer 146091 by jim_thompson5910(28536) About Me  on 2009-05-04 18:49:13 (Show Source):
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Since the times are the same, the time is simply "t" for both equations.


So we have the equations

2100=%28400%2Bw%29t

1900=%28400-w%29t



2100=%28400%2Bw%29t Start with the first equation.


2100%2F%28400%2Bw%29=t Divide both sides by 400%2Bw.


t=2100%2F%28400%2Bw%29 Rearrange the equation


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


1900=%28400-w%29t Move onto the second equation


1900=%28400-w%29%282100%2F%28400%2Bw%29%29 Plug in t=2100%2F%28400%2Bw%29


1900%28400%2Bw%29=%28400-w%292100 Multiply both sides by 400%2Bw.


1900%28400%2Bw%29=2100%28400-w%29 Rearrange the terms.


760000%2B1900w=840000-2100w Distribute.


1900w=840000-2100w-760000 Subtract 760000 from both sides.


1900w%2B2100w=840000-760000 Add 2100w to both sides.


4000w=840000-760000 Combine like terms on the left side.


4000w=80000 Combine like terms on the right side.


w=%2880000%29%2F%284000%29 Divide both sides by 4000 to isolate w.


w=20 Reduce.


So the speed of the wind is 20 mph.


Human-and-algebraic-language/194722: For what real number k does 3x2  k factor as
3(x  2)(x + 2)?
1 solutions

Answer 146090 by jim_thompson5910(28536) About Me  on 2009-05-04 18:16:48 (Show Source):
You can put this solution on YOUR website!
Since we want 3x%5E2-k to factor to 3%28x-2%29%28x%2B2%29, this means that we want 3x%5E2-k=3%28x-2%29%28x%2B2%29


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


3x%5E2-k=3%28x%5E2%2B2x-2x-4%29 FOIL


3x%5E2-k=3%28x%5E2-4%29 Combine like terms.


3x%5E2-k=3x%5E2-12 Distribute


-k=-12 Subtract 3x%5E2 from both sides.


k=12 Divide both sides by -1 to isolate "k".


So the solution is k=12 which means that 3x%5E2-12 factors to 3%28x-2%29%28x%2B2%29


Complex_Numbers/194674: This question is from textbook An Introduction to Abstract Algebra with Notes to the Future Teacher
with the help of the quadratic formula, find all the complex roots of each of the polynomials given in exercise 1.
iii) z^3 + i
1 solutions

Answer 146065 by jim_thompson5910(28536) About Me  on 2009-05-04 15:57:40 (Show Source):
You can put this solution on YOUR website!
First, perform synthetic division on the polynomial z%5E3%2Bi using the test zero z=i. Note: you can easily solve for "z" and find that one solution is z=i

i |  1  0  0   i
  |     i  -1  -i
  -----------
     1  i  -1   0


Since the first three numbers in the third row are 1, i, and -1, this means that

z%5E3%2Bi=%28z-i%29%28z%5E2%2Biz-1%29


Now simply use the quadratic formula to solve z%5E2%2Biz-1=0 for "z":


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


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


z+=+%28-i+%2B-+sqrt%28+-1-4%281%29%28-1%29+%29%29%2F%282%281%29%29 Square i to get i%5E2=%28sqrt%28-1%29%29%5E2=-1.


z+=+%28-i+%2B-+sqrt%28+-1%2B4+%29%29%2F%282%29 Multiply


z+=+%28-i+%2B-+sqrt%28+3+%29%29%2F%282%29 Combine like terms.


So the other two solutions are z+=+%28-i+%2B+sqrt%28+3+%29%29%2F%282%29 or z+=+%28-i+-+sqrt%28+3+%29%29%2F%282%29


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

Answer:

So the 3 solutions are z=i, z+=+%28-i+%2B+sqrt%28+3+%29%29%2F%282%29, or z+=+%28-i+-+sqrt%28+3+%29%29%2F%282%29


Radicals/194682: This question is from textbook Florida Algebra 1
I need help with this problem: A rectangle is 7 times as long as it is wide. Its area is 1400cm^2. Find the dimensions of the rectangle in simplest radical form.
I have been working on this problem for 30 minutes straight, and I can't find the way to work it out. I tried to use this equaion to solve the problem (length=7w): 1400=+2%287w%29+%2A+2w
I didn't work. Please help me.
1 solutions

Answer 146059 by jim_thompson5910(28536) About Me  on 2009-05-04 15:37:05 (Show Source):
You can put this solution on YOUR website!
I'm not sure how you got what you have, but I think you're confusing the area and perimeter formulas.

Since "A rectangle is 7 times as long as it is wide", this means that L=7W. Also, because "Its area is 1400cm^2", we know that A=1400


Recall, the area of a rectangle is A=LW


A=LW Start with the area of a rectangle formula


1400=7W%2AW Plug in L=7W and A=1400


1400=7W%5E2 Multiply


1400%2F7=W%5E2 Divide both sides by 7


200=W%5E2 Reduce


W%5E2=200 Rearrange the equation


W=sqrt%28200%29 Take the square root of both sides. Note: we're only considering the positive square root.


W=sqrt%28100%2A2%29 Factor 200 to get 100*2


W=sqrt%28100%29%2Asqrt%282%29 Break up the square root.


W=10%2Asqrt%282%29 Take the square root of 100 to get 10


L=7W Go back to the first equation


L=7%2A10%2Asqrt%282%29 Plug in W=10%2Asqrt%282%29


L=70%2Asqrt%282%29 Multiply



So the length is 70%2Asqrt%282%29 cm and the width is 10%2Asqrt%282%29 cm


Radicals/194619: Hi! What is radical 3x+1=5
1 solutions

Answer 146007 by jim_thompson5910(28536) About Me  on 2009-05-04 11:36:04 (Show Source):
You can put this solution on YOUR website!
sqrt%283x%2B1%29=5 Start with the given equation


3x%2B1=5%5E2 Square both sides


3x%2B1=25 Square 5 to get 25


3x=25-1 Subtract 1 from both sides.


3x=24 Combine like terms on the right side.


x=%2824%29%2F%283%29 Divide both sides by 3 to isolate x.


x=8 Reduce.


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

Answer:

So the solution is x=8


Graphs/194499: Please help me solve I'm having trouble with graphing y=-2/3x-12 I know how to point them on the graph but I'm having trouble solving the equation to determine if the point's (-4, 10) are correct. no text book
1 solutions

Answer 145935 by jim_thompson5910(28536) About Me  on 2009-05-03 19:30:31 (Show Source):
You can put this solution on YOUR website!

Looking at y=-%282%2F3%29x-12 we can see that the equation is in slope-intercept form y=mx%2Bb where the slope is m=-2%2F3 and the y-intercept is b=-12


Since b=-12 this tells us that the y-intercept is .Remember the y-intercept is the point where the graph intersects with the y-axis

So we have one point




Now since the slope is comprised of the "rise" over the "run" this means
slope=rise%2Frun

Also, because the slope is -2%2F3, this means:

rise%2Frun=-2%2F3


which shows us that the rise is -2 and the run is 3. This means that to go from point to point, we can go down 2 and over 3



So starting at , go down 2 units


and to the right 3 units to get to the next point



Now draw a line through these points to graph y=-%282%2F3%29x-12



So this is the graph of y=-%282%2F3%29x-12 through the points and


Radicals/194496: 5x squared + 2x - 3 = 0
I added 3 on both sides.
5x squared + 2x = 3
But i'm a bit lost.
Someone please help me. I'd provide you with a book but we don't use books in my math class.
1 solutions

Answer 145934 by jim_thompson5910(28536) About Me  on 2009-05-03 19:27:26 (Show Source):
You can put this solution on YOUR website!

5x%5E2%2B2x-3=0 Start with the given equation.


Notice we have a quadratic equation in the form of ax%5E2%2Bbx%2Bc where a=5, b=2, and c=-3


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-%282%29+%2B-+sqrt%28+%282%29%5E2-4%285%29%28-3%29+%29%29%2F%282%285%29%29 Plug in a=5, b=2, and c=-3


x+=+%28-2+%2B-+sqrt%28+4-4%285%29%28-3%29+%29%29%2F%282%285%29%29 Square 2 to get 4.


x+=+%28-2+%2B-+sqrt%28+4--60+%29%29%2F%282%285%29%29 Multiply 4%285%29%28-3%29 to get -60


x+=+%28-2+%2B-+sqrt%28+4%2B60+%29%29%2F%282%285%29%29 Rewrite sqrt%284--60%29 as sqrt%284%2B60%29


x+=+%28-2+%2B-+sqrt%28+64+%29%29%2F%282%285%29%29 Add 4 to 60 to get 64


x+=+%28-2+%2B-+sqrt%28+64+%29%29%2F%2810%29 Multiply 2 and 5 to get 10.


x+=+%28-2+%2B-+8%29%2F%2810%29 Take the square root of 64 to get 8.


x+=+%28-2+%2B+8%29%2F%2810%29 or x+=+%28-2+-+8%29%2F%2810%29 Break up the expression.


x+=+%286%29%2F%2810%29 or x+=++%28-10%29%2F%2810%29 Combine like terms.


x+=+3%2F5 or x+=+-1 Simplify.


So the answers are x+=+3%2F5 or x+=+-1



Quadratic_Equations/194493: find the equation of a quadric function with x- intercepts (2,0) and (-7,0) and y intercept (0,5)
please i need help for this problem please i need help i have exam on Tuesday 05/07/09 so it is urgent!!!!!
1 solutions

Answer 145933 by jim_thompson5910(28536) About Me  on 2009-05-03 19:26:23 (Show Source):
You can put this solution on YOUR website!
Since the equation has the x- intercepts (2,0) and (-7,0), this means that the roots are x=2 or x=-7


x=2 or x=-7 Start with the given roots.


x-2=0 or x%2B7=0 Get everything to the left side.


a%28x-2%29%28x%2B7%29=0 Combine the equations using the zero product property. Also, insert the variable "a" (this will be used to make the graph have a y-intercept of (0,5))


a%28x%5E2%2B5x-14%29=0 FOIL



So the general equation with the x- intercepts (2,0) and (-7,0) is: y=a%28x%5E2%2B5x-14%29



y=a%28x%5E2%2B5x-14%29 Start with the given equation.


y=ax%5E2%2B5ax-14a Distribute


5=a%2A0%5E2%2B5a%280%29-14a Plug in x=0 and y=5 (from the point (0,5))


5=-14a Multiply and simplify


5%2F%28-14%29=a Divide both sides by -14.


a=-5%2F14 Reduce and rearrange the equation.



y=ax%5E2%2B5ax-14a Go back to the previous equation


y=-%285%2F14%29x%5E2%2B5%28-5%2F14%29x-14%28-5%2F14%29 Plug in a=-5%2F14


y=-%285%2F14%29%2Ax%5E2-%2825%2F14%29x%2B5 Multiply and simplify



So the quadratic equation is y=-%285%2F14%29%2Ax%5E2-%2825%2F14%29x%2B5


Here's a graph to visually confirm the answer:




Quadratic_Equations/194491: x squared - 10x + 9 = 0
I subtracted 9 on both sides.
x squared - 10x = -9
and I'm lost from here. Can someone please help me?
1 solutions

Answer 145931 by jim_thompson5910(28536) About Me  on 2009-05-03 19:14:34 (Show Source):
You can put this solution on YOUR website!
Note: because this is a quadratic and there are two terms that involve "x", you can't isolate "x" using linear techniques.


x%5E2-10x%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=-10, 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-%28-10%29+%2B-+sqrt%28+%28-10%29%5E2-4%281%29%289%29+%29%29%2F%282%281%29%29 Plug in a=1, b=-10, and c=9


x+=+%2810+%2B-+sqrt%28+%28-10%29%5E2-4%281%29%289%29+%29%29%2F%282%281%29%29 Negate -10 to get 10.


x+=+%2810+%2B-+sqrt%28+100-4%281%29%289%29+%29%29%2F%282%281%29%29 Square -10 to get 100.


x+=+%2810+%2B-+sqrt%28+100-36+%29%29%2F%282%281%29%29 Multiply 4%281%29%289%29 to get 36


x+=+%2810+%2B-+sqrt%28+64+%29%29%2F%282%281%29%29 Subtract 36 from 100 to get 64


x+=+%2810+%2B-+sqrt%28+64+%29%29%2F%282%29 Multiply 2 and 1 to get 2.


x+=+%2810+%2B-+8%29%2F%282%29 Take the square root of 64 to get 8.


x+=+%2810+%2B+8%29%2F%282%29 or x+=+%2810+-+8%29%2F%282%29 Break up the expression.


x+=+%2818%29%2F%282%29 or x+=++%282%29%2F%282%29 Combine like terms.


x+=+9 or x+=+1 Simplify.


So the answers are x+=+9 or x+=+1



logarithm/194487: Explain how to get the graph of the function f(x)=e^(x-2)+3 from the graph of the function g(x)=e^x.
1 solutions

Answer 145926 by jim_thompson5910(28536) About Me  on 2009-05-03 18:50:26 (Show Source):
You can put this solution on YOUR website!
Start with the graph of g%28x%29=e%5Ex





Now shift the graph over 2 units to the right to graph y=e%5E%28x-2%29




Graph of g%28x%29=e%5Ex (red) and y=e%5E%28x-2%29 (green)




Finally, shift the previous graph up 3 units to get the graph of f%28x%29=e%5E%28x-2%29%2B3




Graph of g%28x%29=e%5Ex (red), y=e%5E%28x-2%29 (green), and f%28x%29=e%5E%28x-2%29%2B3 (blue)


So the graph of f%28x%29=e%5E%28x-2%29%2B3 is





Surface-area/194484: This question is from textbook
I am completely lost on solving this question. Please help.
Find the unknown length, width, or height of the rectangular prism.
V=120m^3, l=4m, w=_____, h=5m
1 solutions

Answer 145922 by jim_thompson5910(28536) About Me  on 2009-05-03 18:33:41 (Show Source):
You can put this solution on YOUR website!
V=LWH Start with the volume of a rectangular prism formula.


120=4x%2A5 Plug in the volume of V=120 and the length and height of L=4 and H=5. We'll use "x" for the unknown width.


120=20x Multiply


120%2F20=x Divide both sides by 20 to isolate "x"


6=x Reduce


So the solution is x=6 which means that the length is 6 meters.