SOLUTION: I am working on an assignment and can not figure out the following problems can you show me how to get the correct answers? 1. (32x^3-48x^2-56x-12)/ (8x+4) 2.I have to convert th

Algebra ->  Equations -> SOLUTION: I am working on an assignment and can not figure out the following problems can you show me how to get the correct answers? 1. (32x^3-48x^2-56x-12)/ (8x+4) 2.I have to convert th      Log On


   

Question 318247: I am working on an assignment and can not figure out the following problems can you show me how to get the correct answers? 1. (32x^3-48x^2-56x-12)/ (8x+4) 2.I have to convert this to a decimal notation and am not sure how to go about it 10^-3 3.r^2+15r=0 I am looking for the solution to r how would I find it? 4. factor by grouping gives me trouble could you show me how to do it? 3x^3-24x^2-5x+40 5.(r-45+7)+(5r+3s)+s+2)
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
1. %2832x%5E3-48x%5E2-56x-12%29%2F+%288x%2B4%29
Factor out 4
%284%288x%5E3-12x%5E2-14x-3%29%29%2F+%284%282x%2B1%29%29
cancel the 4's
%288x%5E3-12x%5E2-14x-3%29%2F+%282x%2B1%29
using long division:
------ _________________________
(2x+1)| 8x^3 - 12x^2 - 14x - 3
you will get quotient of: 4x^2 - 8x - 3
:
:
2.I have to convert this to a decimal notation and am not sure how to go about it
10^-3 = .001; prove this on your calc; enter 10^-3
:
3.r^2+15r = 0 I am looking for the solution to r how would I find it?
Factor out r
r(r + 15) = 0
two solutions
r = 0
r = -15
:
:
4. factor by grouping gives me trouble could you show me how to do it? 3x^3-24x^2-5x+40
Factor out 3x^2 on the 1st two terms, factor out 5 on the last two terms
Note when you factor out -5, it makes it a MINUS 8
3x^2(x-8) - 5(x-8)
Factor out (x-8) from each term; you are left with:
(x-8)(3x^2 - 5)
:
;
5.(r-45+7)+(5r+3s)+(s+2)
plus in front of the brackets so just remove them:
r-45+7+5r+3s+s+2
Group like terms
r + 5r + 3s + s - 45 + 7 + 2
6r + 4s - 36
Factor out 2
2(3r + 2s - 18)