SOLUTION: Solve and then check, show all work 15x+12=-3x^2

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Solve and then check, show all work 15x+12=-3x^2      Log On


   

Question 965743: Solve and then check, show all work
15x+12=-3x^2
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
Solve and then check, show all work
15x+12=-3x^2
3x^2+15x+12=0
x^2+5x+4=0
(x+4)(x+1)=0
x=-4
or
x=-1
check:
f(-4)
15*-4+12=-3*(-4)^2
-60+12=-48
-48=-48
..
f(-1)
15*-1+12=-3*(-1)^2
-3=-3
check ok