SOLUTION: Solve equation by factoring 1.) 2X^2-5X-3=0 2.) X^2+2X=8 3.) 2X^3-X^2-28X=0 4.) X^2-81=0

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Solve equation by factoring 1.) 2X^2-5X-3=0 2.) X^2+2X=8 3.) 2X^3-X^2-28X=0 4.) X^2-81=0       Log On


   

Question 169004: Solve equation by factoring
1.) 2X^2-5X-3=0
2.) X^2+2X=8
3.) 2X^3-X^2-28X=0
4.) X^2-81=0
Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
1.) 2X^2-5X-3=0
(2x+1)(x-3) = 0
x = {-1/2, 3}
.
2.) X^2+2X=8
X^2+2X-8=0
(x-2)(x+4) = 0
x = {-4, 2}
.
3.) 2X^3-X^2-28X=0
x(2x^2-x-28)=0
x(2x+7)(x-4)=0
x = {-7/2, 0, 4}
.
4.) X^2-81=0
(x+9)(x-9) = 0
x = {-9, 9}