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Polynomials-and-rational-expressions/387234: Not understanding please help?
Completely factor the expression
27x2y + 180xy2 + 75y3

1 solutions

Answer 273712 by jim_thompson5910(28715) About Me  on 2010-12-16 20:58:55 (Show Source):
You can put this solution on YOUR website!

27x%5E2y%2B180xy%5E2%2B75y%5E3 Start with the given expression.


3y%289x%5E2%2B60xy%2B25y%5E2%29 Factor out the GCF 3y.


Now let's try to factor the inner expression 9x%5E2%2B60xy%2B25y%5E2


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


Looking at the expression 9x%5E2%2B60xy%2B25y%5E2, we can see that the first coefficient is 9, the second coefficient is 60, and the last coefficient is 25.


Now multiply the first coefficient 9 by the last coefficient 25 to get %289%29%2825%29=225.


Now the question is: what two whole numbers multiply to 225 (the previous product) and add to the second coefficient 60?


To find these two numbers, we need to list all of the factors of 225 (the previous product).


Factors of 225:
1,3,5,9,15,25,45,75,225
-1,-3,-5,-9,-15,-25,-45,-75,-225


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


These factors pair up and multiply to 225.
1*225 = 225
3*75 = 225
5*45 = 225
9*25 = 225
15*15 = 225
(-1)*(-225) = 225
(-3)*(-75) = 225
(-5)*(-45) = 225
(-9)*(-25) = 225
(-15)*(-15) = 225

Now let's add up each pair of factors to see if one pair adds to the middle coefficient 60:


First NumberSecond NumberSum
12251+225=226
3753+75=78
5455+45=50
9259+25=34
151515+15=30
-1-225-1+(-225)=-226
-3-75-3+(-75)=-78
-5-45-5+(-45)=-50
-9-25-9+(-25)=-34
-15-15-15+(-15)=-30



From the table, we can see that there are no pairs of numbers which add to 60. So 9x%5E2%2B60xy%2B25y%5E2 cannot be factored.


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



Answer:


So 27x%5E2y%2B180xy%5E2%2B75y%5E3 simply factors to 3y%289x%5E2%2B60xy%2B25y%5E2%29


In other words, 27x%5E2y%2B180xy%5E2%2B75y%5E3=3y%289x%5E2%2B60xy%2B25y%5E2%29.


If you need more help, email me at
jim_thompson5910@hotmail.com

Also, feel free to check out my tutoring website

Jim


Geometry_proofs/387192: Write an indirect proof for,
Given: n squared is even
Prove: n squared is divisible by 4

1 solutions

Answer 273693 by jim_thompson5910(28715) About Me  on 2010-12-16 20:32:41 (Show Source):
You can put this solution on YOUR website!
The idea is that if n%5E2 is even, then n is even (you can prove this by contraposition). So n=2k for some integer k.


So n%5E2=%282k%29%5E2=4k%5E2. So because n%5E2=4k%5E2, this means that n%5E2 is a multiple of 4.


Rational-functions/387205: algebra 2:
i found the "hole" using a given function, and graphed it. r graphs w/ holes always linear?
1 solutions

Answer 273691 by jim_thompson5910(28715) About Me  on 2010-12-16 20:30:25 (Show Source):
You can put this solution on YOUR website!
No, it's perfectly possible for a non-linear equation to have a hole in it.


Ex: f%28x%29=%28x%2B3%29%2F%28x%5E3%2B3x%5E2-4x-12%29 has a hole at x=-3 and it's non-linear.


Polynomials-and-rational-expressions/387220: In class we are trying to factor special products; trinomials to be specific. We need to get it in perfect square trinomial pattern. Here's the question:
9t^2-12t+4
Thanks
1 solutions

Answer 273690 by jim_thompson5910(28715) About Me  on 2010-12-16 20:27:08 (Show Source):
You can put this solution on YOUR website!

Looking at the expression 9t%5E2-12t%2B4, we can see that the first coefficient is 9, the second coefficient is -12, and the last term is 4.


Now multiply the first coefficient 9 by the last term 4 to get %289%29%284%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 = 36
2*18 = 36
3*12 = 36
4*9 = 36
6*6 = 36
(-1)*(-36) = 36
(-2)*(-18) = 36
(-3)*(-12) = 36
(-4)*(-9) = 36
(-6)*(-6) = 36

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 -12t with -6t-6t. Remember, -6 and -6 add to -12. So this shows us that -6t-6t=-12t.


9t%5E2%2Bhighlight%28-6t-6t%29%2B4 Replace the second term -12t with -6t-6t.


%289t%5E2-6t%29%2B%28-6t%2B4%29 Group the terms into two pairs.


3t%283t-2%29%2B%28-6t%2B4%29 Factor out the GCF 3t from the first group.


3t%283t-2%29-2%283t-2%29 Factor out 2 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.


%283t-2%29%283t-2%29 Combine like terms. Or factor out the common term 3t-2


%283t-2%29%5E2 Condense the terms.


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


Answer:


So 9t%5E2-12t%2B4 factors to %283t-2%29%5E2.


In other words, 9t%5E2-12t%2B4=%283t-2%29%5E2.


Note: you can check the answer by expanding %283t-2%29%5E2 to get 9t%5E2-12t%2B4 or by graphing the original expression and the answer (the two graphs should be identical).


If you need more help, email me at jim_thompson5910@hotmail.com

Also, feel free to check out my tutoring website

Jim


Numbers_Word_Problems/387218: It is a 2-digit number
Its digits add up to 13.
It has more tens than ones.
There are three answers that fit these clues.
1 solutions

Answer 273689 by jim_thompson5910(28715) About Me  on 2010-12-16 20:25:53 (Show Source):
You can put this solution on YOUR website!
Hints: "It is a 2-digit number" means that that number is in the form 10a%2Bb where 'a' is the tens digit and 'b' is the units digit.


"Its digits add up to 13." means that a%2Bb=13


"It has more tens than ones. " means that a%3Eb



Quadratic_Equations/387207: I came across a word problem type of quadratic equation that I am having a hint of trouble understanding.
problem: every root of x^2-5x-6=0 is one greater than a root of x^2+px+q=0.
What does p equal?

What I did was, I found the factors of x^2-5x-6=0
I received x = -1, 6 as the factors.
But what does it mean by root and greater? I am confused after this part of the question. WOuld the answer be
0, 7?
1 solutions

Answer 273687 by jim_thompson5910(28715) About Me  on 2010-12-16 20:23:41 (Show Source):
You can put this solution on YOUR website!
0,7 are the roots of x^2+px+q=0


You now have to use that idea to construct a quadratic


Hint: If 'a' and 'b' are roots of a polynomial, then %28x-a%29%28x-b%29=0


Miscellaneous_Word_Problems/387141: Could someone help me solve this problem using quadratic formula step by step. I am lost and do not understand.
x^2+4x+3=0
Thank you
1 solutions

Answer 273658 by jim_thompson5910(28715) About Me  on 2010-12-16 17:41:52 (Show Source):
You can put this solution on YOUR website!

x%5E2%2B4x%2B3=0 Start with the given equation.


Notice that the quadratic x%5E2%2B4x%2B3 is in the form of Ax%5E2%2BBx%2BC where A=1, B=4, 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-%284%29+%2B-+sqrt%28+%284%29%5E2-4%281%29%283%29+%29%29%2F%282%281%29%29 Plug in A=1, B=4, and C=3


x+=+%28-4+%2B-+sqrt%28+16-4%281%29%283%29+%29%29%2F%282%281%29%29 Square 4 to get 16.


x+=+%28-4+%2B-+sqrt%28+16-12+%29%29%2F%282%281%29%29 Multiply 4%281%29%283%29 to get 12


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


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


x+=+%28-4+%2B-+2%29%2F%282%29 Take the square root of 4 to get 2.


x+=+%28-4+%2B+2%29%2F%282%29 or x+=+%28-4+-+2%29%2F%282%29 Break up the expression.


x+=+%28-2%29%2F%282%29 or x+=++%28-6%29%2F%282%29 Combine like terms.


x+=+-1 or x+=+-3 Simplify.


So the solutions are x+=+-1 or x+=+-3


If you need more help, email me at jim_thompson5910@hotmail.com

Also, feel free to check out my tutoring website

Jim


Equations/387109: what is the factored form of 4k^3-13k^2-12k
1 solutions

Answer 273633 by jim_thompson5910(28715) About Me  on 2010-12-16 16:18:34 (Show Source):
You can put this solution on YOUR website!

4k%5E3-13k%5E2-12k Start with the given expression.


k%284k%5E2-13k-12%29 Factor out the GCF k.


Now let's try to factor the inner expression 4k%5E2-13k-12


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


Looking at the expression 4k%5E2-13k-12, we can see that the first coefficient is 4, the second coefficient is -13, and the last term is -12.


Now multiply the first coefficient 4 by the last term -12 to get %284%29%28-12%29=-48.


Now the question is: what two whole numbers multiply to -48 (the previous product) and add to the second coefficient -13?


To find these two numbers, we need to list all of the factors of -48 (the previous product).


Factors of -48:
1,2,3,4,6,8,12,16,24,48
-1,-2,-3,-4,-6,-8,-12,-16,-24,-48


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


These factors pair up and multiply to -48.
1*(-48) = -48
2*(-24) = -48
3*(-16) = -48
4*(-12) = -48
6*(-8) = -48
(-1)*(48) = -48
(-2)*(24) = -48
(-3)*(16) = -48
(-4)*(12) = -48
(-6)*(8) = -48

Now let's add up each pair of factors to see if one pair adds to the middle coefficient -13:


First NumberSecond NumberSum
1-481+(-48)=-47
2-242+(-24)=-22
3-163+(-16)=-13
4-124+(-12)=-8
6-86+(-8)=-2
-148-1+48=47
-224-2+24=22
-316-3+16=13
-412-4+12=8
-68-6+8=2



From the table, we can see that the two numbers 3 and -16 add to -13 (the middle coefficient).


So the two numbers 3 and -16 both multiply to -48 and add to -13


Now replace the middle term -13k with 3k-16k. Remember, 3 and -16 add to -13. So this shows us that 3k-16k=-13k.


4k%5E2%2Bhighlight%283k-16k%29-12 Replace the second term -13k with 3k-16k.


%284k%5E2%2B3k%29%2B%28-16k-12%29 Group the terms into two pairs.


k%284k%2B3%29%2B%28-16k-12%29 Factor out the GCF k from the first group.


k%284k%2B3%29-4%284k%2B3%29 Factor out 4 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.


%28k-4%29%284k%2B3%29 Combine like terms. Or factor out the common term 4k%2B3


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


So k%284k%5E2-13k-12%29 then factors further to k%28k-4%29%284k%2B3%29


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


Answer:


So 4k%5E3-13k%5E2-12k completely factors to k%28k-4%29%284k%2B3%29.


In other words, 4k%5E3-13k%5E2-12k=k%28k-4%29%284k%2B3%29.


Note: you can check the answer by expanding k%28k-4%29%284k%2B3%29 to get 4k%5E3-13k%5E2-12k or by graphing the original expression and the answer (the two graphs should be identical).


If you need more help, email me at jim_thompson5910@hotmail.com

Also, feel free to check out my tutoring website

Jim


Proofs/387106: (X->Y)->Z, W->(X->Y) therefore W->Z
Can I just say hyp syllogism where (x->y)is one thing?
1 solutions

Answer 273632 by jim_thompson5910(28715) About Me  on 2010-12-16 16:17:33 (Show Source):
You can put this solution on YOUR website!
Yes, you would use a hypothetical syllogism to combine the two expressions.


Remember, the Hypothetical Syllogism (H.S.) is
   p -> q  
   q -> r  
:. p -> r




In this case, p is W, q is (X->Y), and r is Z.


Probability-and-statistics/386775: A weighted coin is tossed four times. The probability for the number of heads observed is given below.
#Heads Probability
0 .4096
1 .4096
2 .1536
3 .0256
4 .0016
What is the probability pf getting AT LEAST one head?
1 solutions

Answer 273364 by jim_thompson5910(28715) About Me  on 2010-12-15 19:26:58 (Show Source):
You can put this solution on YOUR website!
"at least one head" means "1 OR more heads"


So all you have to do is add up all the probabilities of getting 1, 2, 3, or 4 heads to find your answer.




Permutations/386769: If nPr = 120, and nCr=20, then determine the value of 7Pr.
1 solutions

Answer 273363 by jim_thompson5910(28715) About Me  on 2010-12-15 19:25:19 (Show Source):
You can put this solution on YOUR website!
Hint: Use the idea that n P r = r! * (n C r)


Evaluation_Word_Problems/386708: i took 7 tests.
my median score is 90.
the range of scores is 18.
what are the 7 test scores?
1 solutions

Answer 273340 by jim_thompson5910(28715) About Me  on 2010-12-15 18:19:42 (Show Source):
You can put this solution on YOUR website!
You would need more information. All you can really find out are the highest and lowest possible scores.


Lowest Score = Median - (range/2) = 90 - 18/2 = 90 - 9 = 81

So the lowest possible score is 81


Highest Score = Median + (range/2) = 90 + 18/2 = 90 + 9 = 99

So the highest possible score is 99


Equations/385789: 5x+1=6
1 solutions

Answer 272877 by jim_thompson5910(28715) About Me  on 2010-12-13 20:56:50 (Show Source):
You can put this solution on YOUR website!
5x%2B1=6 Start with the given equation.


5x=6-1 Subtract 1 from both sides.


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


x=%285%29%2F%285%29 Divide both sides by 5 to isolate x.


x=1 Reduce.


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

Answer:

So the solution is x=1


If you need more help, email me at jim_thompson5910@hotmail.com

Also, feel free to check out my tutoring website

Jim


Linear-equations/385761: Write the slope-intercept equation for the line that passes through (2, -7) and (4, -13). Please show all of your work
1 solutions

Answer 272868 by jim_thompson5910(28715) About Me  on 2010-12-13 20:36:44 (Show Source):
You can put this solution on YOUR website!

First let's find the slope of the line through the points and


Note: is the first point . So this means that x%5B1%5D=2 and y%5B1%5D=-7.
Also, is the second point . So this means that x%5B2%5D=4 and y%5B2%5D=-13.


m=%28y%5B2%5D-y%5B1%5D%29%2F%28x%5B2%5D-x%5B1%5D%29 Start with the slope formula.


m=%28-13--7%29%2F%284-2%29 Plug in y%5B2%5D=-13, y%5B1%5D=-7, x%5B2%5D=4, and x%5B1%5D=2


m=%28-6%29%2F%284-2%29 Subtract -7 from -13 to get -6


m=%28-6%29%2F%282%29 Subtract 2 from 4 to get 2


m=-3 Reduce


So the slope of the line that goes through the points and is m=-3


Now let's use the point slope formula:


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


y--7=-3%28x-2%29 Plug in m=-3, x%5B1%5D=2, and y%5B1%5D=-7


y%2B7=-3%28x-2%29 Rewrite y--7 as y%2B7


y%2B7=-3x%2B-3%28-2%29 Distribute


y%2B7=-3x%2B6 Multiply


y=-3x%2B6-7 Subtract 7 from both sides.


y=-3x-1 Combine like terms.



So the equation that goes through the points and is y=-3x-1


Notice how the graph of y=-3x-1 goes through the points and . So this visually verifies our answer.
Graph of y=-3x-1 through the points and

If you need more help, email me at jim_thompson5910@hotmail.com

Also, feel free to check out my tutoring website

Jim


Polynomials-and-rational-expressions/385283: Please help factor by grouping:
p^2 - q^2 + r^2 - 2pr
This is straight from book.
Thanks for showing steps.
1 solutions

Answer 272604 by jim_thompson5910(28715) About Me  on 2010-12-13 00:35:27 (Show Source):
You can put this solution on YOUR website!
p%5E2+-+q%5E2+%2B+r%5E2+-+2pr Start with the given expression.


p%5E2+-+2pr+%2B+r%5E2+-+q%5E2++ Rearrange the terms.


%28p-r%29%5E2+-+q%5E2++ Factor p%5E2+-+2pr+%2B+r%5E2 to get %28p-r%29%5E2


%28p-r%2Bq%29%28p-r-q%29++ Now use the difference of squares formula to factor.


So p%5E2+-+q%5E2+%2B+r%5E2+-+2pr factors to %28p-r%2Bq%29%28p-r-q%29++


In other words, p%5E2+-+q%5E2+%2B+r%5E2+-+2pr=%28p-r%2Bq%29%28p-r-q%29++


Equations/385286: 3(x-6)+8= 5(x+2)-12
1 solutions

Answer 272592 by jim_thompson5910(28715) About Me  on 2010-12-13 00:06:30 (Show Source):
You can put this solution on YOUR website!
3%28x-6%29%2B8=5%28x%2B2%29-12 Start with the given equation.


3x-18%2B8=5x%2B10-12 Distribute.


3x-10=5x%2B10-12 Combine like terms on the left side.


3x-10=5x-2 Combine like terms on the right side.


3x=5x-2%2B10 Add 10 to both sides.


3x-5x=-2%2B10 Subtract 5x from both sides.


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


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


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


x=-4 Reduce.


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

Answer:

So the solution is x=-4


If you need more help, email me at jim_thompson5910@hotmail.com

Also, feel free to check out my tutoring website

Jim


Equations/385277: I need help solving this 5x-3=11+12x
1 solutions

Answer 272585 by jim_thompson5910(28715) About Me  on 2010-12-12 23:40:18 (Show Source):
You can put this solution on YOUR website!
5x-3=11%2B12x Start with the given equation.


5x=11%2B12x%2B3 Add 3 to both sides.


5x-12x=11%2B3 Subtract 12x from both sides.


-7x=11%2B3 Combine like terms on the left side.


-7x=14 Combine like terms on the right side.


x=%2814%29%2F%28-7%29 Divide both sides by -7 to isolate x.


x=-2 Reduce.


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

Answer:

So the solution is x=-2


If you need more help, email me at jim_thompson5910@hotmail.com

Also, feel free to check out my tutoring website

Jim


Polynomials-and-rational-expressions/385275: Use the “difference of squares” rule to factor the following expression:
36x^2-9y^2

1 solutions

Answer 272584 by jim_thompson5910(28715) About Me  on 2010-12-12 23:28:30 (Show Source):
You can put this solution on YOUR website!

36x%5E2-9y%5E2 Start with the given expression.


%286x%29%5E2-9y%5E2 Rewrite 36x%5E2 as %286x%29%5E2.


%286x%29%5E2-%283y%29%5E2 Rewrite 9y%5E2 as %283y%29%5E2.


Notice how we have a difference of squares A%5E2-B%5E2 where in this case A=6x and B=3y.


So let's use the difference of squares formula A%5E2-B%5E2=%28A%2BB%29%28A-B%29 to factor the expression:


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


%286x%29%5E2-%283y%29%5E2=%286x%2B3y%29%286x-3y%29 Plug in A=6x and B=3y.


So this shows us that 36x%5E2-9y%5E2 factors to %286x%2B3y%29%286x-3y%29.


In other words 36x%5E2-9y%5E2=%286x%2B3y%29%286x-3y%29.


If you need more help, email me at jim_thompson5910@hotmail.com

Also, feel free to check out my tutoring website

Jim


Polynomials-and-rational-expressions/385276: Not understanding, can anyone help?
Factor the expression a^2-6ab+96b^2 into a product of binomials.

1 solutions

Answer 272583 by jim_thompson5910(28715) About Me  on 2010-12-12 23:27:52 (Show Source):
You can put this solution on YOUR website!

Looking at the expression a%5E2-6ab%2B96b%5E2, we can see that the first coefficient is 1, the second coefficient is -6, and the last coefficient is 96.


Now multiply the first coefficient 1 by the last coefficient 96 to get %281%29%2896%29=96.


Now the question is: what two whole numbers multiply to 96 (the previous product) and add to the second coefficient -6?


To find these two numbers, we need to list all of the factors of 96 (the previous product).


Factors of 96:
1,2,3,4,6,8,12,16,24,32,48,96
-1,-2,-3,-4,-6,-8,-12,-16,-24,-32,-48,-96


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


These factors pair up and multiply to 96.
1*96 = 96
2*48 = 96
3*32 = 96
4*24 = 96
6*16 = 96
8*12 = 96
(-1)*(-96) = 96
(-2)*(-48) = 96
(-3)*(-32) = 96
(-4)*(-24) = 96
(-6)*(-16) = 96
(-8)*(-12) = 96

Now let's add up each pair of factors to see if one pair adds to the middle coefficient -6:


First NumberSecond NumberSum
1961+96=97
2482+48=50
3323+32=35
4244+24=28
6166+16=22
8128+12=20
-1-96-1+(-96)=-97
-2-48-2+(-48)=-50
-3-32-3+(-32)=-35
-4-24-4+(-24)=-28
-6-16-6+(-16)=-22
-8-12-8+(-12)=-20



From the table, we can see that there are no pairs of numbers which add to -6. So a%5E2-6ab%2B96b%5E2 cannot be factored.


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



Answer:


So a%5E2-6ab%2B96b%5E2 doesn't factor at all (over the rational numbers).


So a%5E2-6ab%2B96b%5E2 is prime.


If you need more help, email me at
jim_thompson5910@hotmail.com

Also, feel free to check out my tutoring website

Jim


Polynomials-and-rational-expressions/385262: 12y^2+5y-3
1 solutions

Answer 272577 by jim_thompson5910(28715) About Me  on 2010-12-12 23:18:26 (Show Source):
You can put this solution on YOUR website!
I'm assuming you want to factor this.


Looking at the expression 12y%5E2%2B5y-3, we can see that the first coefficient is 12, the second coefficient is 5, and the last term is -3.


Now multiply the first coefficient 12 by the last term -3 to get %2812%29%28-3%29=-36.


Now the question is: what two whole numbers multiply to -36 (the previous product) and add to the second coefficient 5?


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) = -36
2*(-18) = -36
3*(-12) = -36
4*(-9) = -36
6*(-6) = -36
(-1)*(36) = -36
(-2)*(18) = -36
(-3)*(12) = -36
(-4)*(9) = -36
(-6)*(6) = -36

Now let's add up each pair of factors to see if one pair adds to the middle coefficient 5:


First NumberSecond NumberSum
1-361+(-36)=-35
2-182+(-18)=-16
3-123+(-12)=-9
4-94+(-9)=-5
6-66+(-6)=0
-136-1+36=35
-218-2+18=16
-312-3+12=9
-49-4+9=5
-66-6+6=0



From the table, we can see that the two numbers -4 and 9 add to 5 (the middle coefficient).


So the two numbers -4 and 9 both multiply to -36 and add to 5


Now replace the middle term 5y with -4y%2B9y. Remember, -4 and 9 add to 5. So this shows us that -4y%2B9y=5y.


12y%5E2%2Bhighlight%28-4y%2B9y%29-3 Replace the second term 5y with -4y%2B9y.


%2812y%5E2-4y%29%2B%289y-3%29 Group the terms into two pairs.


4y%283y-1%29%2B%289y-3%29 Factor out the GCF 4y from the first group.


4y%283y-1%29%2B3%283y-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.


%284y%2B3%29%283y-1%29 Combine like terms. Or factor out the common term 3y-1


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


Answer:


So 12y%5E2%2B5y-3 factors to %284y%2B3%29%283y-1%29.


In other words, 12y%5E2%2B5y-3=%284y%2B3%29%283y-1%29.


Note: you can check the answer by expanding %284y%2B3%29%283y-1%29 to get 12y%5E2%2B5y-3 or by graphing the original expression and the answer (the two graphs should be identical).


If you need more help, email me at jim_thompson5910@hotmail.com

Also, feel free to check out my tutoring website

Jim


test/385261: Graph the following equation using the intercepts
-4x+8y=-16
What goes on the x and y axis?!?! I'm so confused
1 solutions

Answer 272575 by jim_thompson5910(28715) About Me  on 2010-12-12 23:06:20 (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%2B8y=-16 Start with the given equation.


-4x%2B8%280%29=-16 Plug in y=0.


-4x%2B0=-16 Multiply 8 and 0 to get 0.


-4x=-16 Simplify.


x=%28-16%29%2F%28-4%29 Divide both sides by -4 to isolate x.


x=4 Reduce.


So the x-intercept is .


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


y-intercept


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


-4x%2B8y=-16 Start with the given equation.


-4%280%29%2B8y=-16 Plug in x=0.


-0%2B8y=-16 Multiply -4 and 0 to get 0.


8y=-16 Simplify.


y=%28-16%29%2F%288%29 Divide both sides by 8 to isolate y.


y=-2 Reduce.


So the y-intercept is .


Now let's plot the points and which are the x and y intercepts respectively.





Now draw a straight line through the plotted points to graph -4x%2B8y=-16.


Graph of -4x%2B8y=-16


If you need more help, email me at jim_thompson5910@hotmail.com

Also, feel free to check out my tutoring website

Jim


Equations/385259: Determine whether the given number is a solution to the equation following it.
5,3x-7=2x+1

1 solutions

Answer 272574 by jim_thompson5910(28715) About Me  on 2010-12-12 23:04:13 (Show Source):
You can put this solution on YOUR website!
3x-7=2x%2B1 Start with the given equation.


3%2A%285%29-7=2%2A%285%29%2B1 Plug in x=5.


8=2%2A%285%29%2B1 Evaluate and simplify the left side.


8=11 Evaluate and simplify the right side.


Since the equation is NOT true, this means that x=5 is NOT a solution.


If you need more help, email me at jim_thompson5910@hotmail.com

Also, feel free to check out my tutoring website

Jim


Conjunction/385135: Truth Table: ~(P=>Q)<=>(P^~Q)
I believe I am on the right path with the following:
P Q P=>Q ~(P=>Q) ~Q P^~Q
t t t t f t
f t t f f f
t f f t t t
f f t f t f
Making this table a neither a tautology or a contrdiction. Would this be correct? Six columns with 4 t or f under each column. They would not line up for me so I hope this is understandable.
Melody

1 solutions

Answer 272524 by jim_thompson5910(28715) About Me  on 2010-12-12 20:11:08 (Show Source):
You can put this solution on YOUR website!
The truth table for ~(P=>Q)<=>(P^~Q) is

PQP => Q~(P => Q)~QP ^ ~Q~(P => Q) <=> (P ^ ~Q)
TTTFFFT
TFFTTTT
FTTFFFT
FFTFTFT



which means that we have a tautology.


If you need more help, email me at jim_thompson5910@hotmail.com

Also, feel free to check out my tutoring website

Jim


Probability-and-statistics/384642: given that p(a)=0.4, p(b)=0.4, and p(a and b)=0.10, determine p(a|b)
1 solutions

Answer 272333 by jim_thompson5910(28715) About Me  on 2010-12-12 04:17:37 (Show Source):
You can put this solution on YOUR website!
Using the idea that

P(A | B) = P(A and B)/P(B), this means that


p(a|b) = p(a and b)/p(b)

p(a|b) = 0.10/0.4=0.25


So p(a|b) = 0.25


Numeric_Fractions/384713: I don't believe 8x to the 3rd power (exponent over the x)divided by 15y to the 3rd(exponent 3 over the y)can be reduced to anything. The answer is the fraction, 8x3/15y3
Correct or wrong? there is nothing to reduce. Is this correct or not? Thanks
1 solutions

Answer 272332 by jim_thompson5910(28715) About Me  on 2010-12-12 04:15:22 (Show Source):
You can put this solution on YOUR website!
You are correct, %288x%5E3%29%2F%2815y%5E3%29 does not simplify any further. However, we have no way of checking whether %288x%5E3%29%2F%2815y%5E3%29 is the answer (as you haven't posted the actual problem).


Polynomials-and-rational-expressions/384695: OK, last weary question for the night: have I gotten this one right??
4x^2 - 21x + 20
(4x^2 - 25x) + (4x = 20)
x(4^2 - 25) + (4(x + 5) = (4^2 -25)(x+4)??????????????
thanks in advance - and where've y'all been all my life????????
1 solutions

Answer 272331 by jim_thompson5910(28715) About Me  on 2010-12-12 04:13:31 (Show Source):
You can put this solution on YOUR website!

Looking at the expression 4x%5E2-21x%2B20, we can see that the first coefficient is 4, the second coefficient is -21, and the last term is 20.


Now multiply the first coefficient 4 by the last term 20 to get %284%29%2820%29=80.


Now the question is: what two whole numbers multiply to 80 (the previous product) and add to the second coefficient -21?


To find these two numbers, we need to list all of the factors of 80 (the previous product).


Factors of 80:
1,2,4,5,8,10,16,20,40,80
-1,-2,-4,-5,-8,-10,-16,-20,-40,-80


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


These factors pair up and multiply to 80.
1*80 = 80
2*40 = 80
4*20 = 80
5*16 = 80
8*10 = 80
(-1)*(-80) = 80
(-2)*(-40) = 80
(-4)*(-20) = 80
(-5)*(-16) = 80
(-8)*(-10) = 80

Now let's add up each pair of factors to see if one pair adds to the middle coefficient -21:


First NumberSecond NumberSum
1801+80=81
2402+40=42
4204+20=24
5165+16=21
8108+10=18
-1-80-1+(-80)=-81
-2-40-2+(-40)=-42
-4-20-4+(-20)=-24
-5-16-5+(-16)=-21
-8-10-8+(-10)=-18



From the table, we can see that the two numbers -5 and -16 add to -21 (the middle coefficient).


So the two numbers -5 and -16 both multiply to 80 and add to -21


Now replace the middle term -21x with -5x-16x. Remember, -5 and -16 add to -21. So this shows us that -5x-16x=-21x.


4x%5E2%2Bhighlight%28-5x-16x%29%2B20 Replace the second term -21x with -5x-16x.


%284x%5E2-5x%29%2B%28-16x%2B20%29 Group the terms into two pairs.


x%284x-5%29%2B%28-16x%2B20%29 Factor out the GCF x from the first group.


x%284x-5%29-4%284x-5%29 Factor out 4 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-4%29%284x-5%29 Combine like terms. Or factor out the common term 4x-5


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


Answer:


So 4x%5E2-21x%2B20 factors to %28x-4%29%284x-5%29.


In other words, 4x%5E2-21x%2B20=%28x-4%29%284x-5%29.


Note: you can check the answer by expanding %28x-4%29%284x-5%29 to get 4x%5E2-21x%2B20 or by graphing the original expression and the answer (the two graphs should be identical).



If you need more help, email me at jim_thompson5910@hotmail.com

Also, feel free to check out my tutoring website

Jim


test/384566: i need help with geometry simalarity right trianglesand trigonometry

If a/b=5/3 then 3a = ____.

1 solutions

Answer 272221 by jim_thompson5910(28715) About Me  on 2010-12-11 18:37:06 (Show Source):
You can put this solution on YOUR website!
Cross multiply to get 3a=5b


Probability-and-statistics/384519: A company that makes shampoo wants to test whether the average amount of shampoo per bottle is 16 ounces. The standard deviation is known to be 0.20 ounces. Assuming that the hypothesis test is to be performed using 0.10 level of significance and a random sample of n = 64 bottles, which of the following would be the correct formulation of the null and alternative hypotheses?
Answer
a.Ho : x-bar = 16HA : x-bar not equal to 16
Ho : u = 16HA : u not equal to 16
Ho : u >16HA : u < 16
Ho : x-bar > 16HA : x-bar <16
1 solutions

Answer 272210 by jim_thompson5910(28715) About Me  on 2010-12-11 16:34:21 (Show Source):
You can put this solution on YOUR website!
You want the null Ho to be very specific. So you want an equation in the null hypothesis. This means that we can rule out the last two choices.


Now because we're doing a test on a population parameter, this means that we're going to be testing mu and NOT . Why? Because we can very easily find the value of for that given sample (since this is the sample mean), so there's no need to test it. However, we can't easily find the value of mu, which means that we need to test it. So this rules out the first choice.


So the answer is

H%5Bo%5D: mu=16
H%5BA%5D: mu%3C%3E16


test/384493: |5x-7|=-5
1 solutions

Answer 272208 by jim_thompson5910(28715) About Me  on 2010-12-11 16:29:47 (Show Source):
You can put this solution on YOUR website!
Since the absolute value of any number is ALWAYS nonnegative, this means that there are no solutions to this equation.


Distributive-associative-commutative-properties/384527: Factor completely.
64 + 27w^3
1 solutions

Answer 272207 by jim_thompson5910(28715) About Me  on 2010-12-11 16:28:55 (Show Source):
You can put this solution on YOUR website!

64%2B27w%5E3 Start with the given expression.


%284%29%5E3%2B%283w%29%5E3 Rewrite 64 as %284%29%5E3. Rewrite 27w%5E3 as %283w%29%5E3.


%284%2B3w%29%28%284%29%5E2-%284%29%283w%29%2B%283w%29%5E2%29 Now factor by using the sum of cubes formula. Remember the sum of cubes formula is A%5E3%2BB%5E3=%28A%2BB%29%28A%5E2-AB%2BB%5E2%29


%284%2B3w%29%2816-12w%2B9w%5E2%29 Multiply

-----------------------------------
Answer:

So 64%2B27w%5E3 factors to %284%2B3w%29%2816-12w%2B9w%5E2%29.

In other words, 64%2B27w%5E3=%284%2B3w%29%2816-12w%2B9w%5E2%29


If you need more help, email me at jim_thompson5910@hotmail.com

Also, feel free to check out my tutoring website

Jim


Sequences-and-series/384539: What is the sum of 56 and 9
1 solutions

Answer 272206 by jim_thompson5910(28715) About Me  on 2010-12-11 16:27:56 (Show Source):