1. ## Answers Check & Question

Are these correct?

1. Multiply:
(10z+5)(z2 - 2z+10)

10z3 - 15z2 + 90z + 50

2. Divide:
16r3 - 12r2+ 60r + 16
------------------------
8r+2
2(r2 - r +4)

3. Divide Synthetically:
(2m3 + 5m2 + 6m -4) / (m +1)

2m2 + 3m + 3 R= -7/m+1

4. Subtract 13r2 - 9r + 3 from 7r2- 4r - 8

-6r2+ 13r +5

5. Divide:
18r3 - 9r2+34r +45
--------------------
6r + 5

3r2 - 4r + 9

6. Factor:
uv2 - 4 - v2+ 4

(u+1)(v2 + 4)

7. Factor:
x2(y-7)2 + 5x(y-7)2 +4(y-7)2

(y-7)2(x+4)(x-1)

8.Factor:
x3 + 125

(x+5)(x2-5x+25)

9. Factor:
16a4 - 1
(4a2+1)(4a2- 1)

10. If g(t) = 2t2+11t-10, find t such that g(t) = 11

g(t) = 353

11. Evaluate:
4x2y2+2x2y - 3xy2- 3xy + 6 when x= -2 and y = 2

-2

12. If P(y) = 1/2y -1 then find y such that P(y)= -5

P(y) = - 13/2

And I need help setting up this problem:
Solve this equation:
n3+80n=18n2

Would you set it up as n3+80n+18n2= 0 ?
I'm not sure what my steps need to be to set it up to try and solve it.

Thank you for any help!

2. ## Re: Answers Check & Question

allow me to introduce you to Wolfram Alpha ...

expand (10z+5)*(z^2 - 2z+10) - Wolfram|Alpha

3. ## Re: Answers Check & Question

I've looked at Wolfram Alpha and many of what I input is not being understood. I am not sure what I am doing wrong with imputing the information? I really need to know if my answers are correct because these are being used as notes for my final tomorrow.

4. ## Re: Answers Check & Question

Originally Posted by Kibbygirl
I've looked at Wolfram Alpha and many of what I input is not being understood. I am not sure what I am doing wrong with imputing the information? I really need to know if my answers are correct because these are being used as notes for my final tomorrow.
Can you show what you tried at Wolfram Alpha that would not work.
Using those examples may give you some ideas.

5. ## Re: Answers Check & Question

the following are incorrect ...

4, 6, 7, 10, 11, and 12

9 is incomplete

$n^3+80n=18n^2$

$n^3-18n^2+80n = 0$

start by factoring out an $n$ , then factor the resulting quadratic factor

6. ## Re: Answers Check & Question

#10 and #12 are ones that it doesn't seem to understand and I am unsure how to put them in so it can understand them. I didn't see it on the examples page.

7. ## Re: Answers Check & Question

Ok thank you. So 1-3, 5, 8 are all incorrect?

8. ## Re: Answers Check & Question

10. If g(t) = 2t^2+11t-10, find t such that g(t) = 11
$2t^2+11t-10 = 11$

$2t^2+11t-21 = 0$

factor and solve

12. If P(y) = 1/2y -1 then find y such that P(y)= -5
$\frac{1}{2y} - 1 = -5$

$\frac{1}{2y} = -4$

$-\frac{1}{4} = 2y$

$-\frac{1}{8} = y$

10. ## Re: Answers Check & Question

Originally Posted by Kibbygirl
#10 and #12 are ones that it doesn't seem to understand and I am unsure how to put them in so it can understand them. I didn't see it on the examples page.
Well look at this,

11. ## Re: Answers Check & Question

How would I put #7 above into the Wolfram site? This problem:
Factor:
x2(y-7)2 + 5x(y-7)2 +4(y-7)2

12. ## Re: Answers Check & Question

Originally Posted by Kibbygirl
How would I put #7 above into the Wolfram site? This problem:
Factor:
x2(y-7)2 + 5x(y-7)2 +4(y-7)2

factor x^2(y-7)^2 + 5x(y-7)^2 +4(y-7)^2 - Wolfram|Alpha

13. ## Re: Answers Check & Question

Thanks skeeter. I typed it in but I must have had spaces in the wrong spot. For #6 above - which I see I had a typo and left off the u on the end after the second 4... --- ; uv2 - 4 - v2+ 4u is the correct answer (u-1)(v2+4)?