Suppose the quadratic function f(x) = ax^2 + bx + c with f(−2) = 0 and -b/2a=1. Solve f(x) = 0

Question

I need help with this problem please :)

Answer 1

1. From f(-2) =0, we get 4a - 2b + c =0
2. Divide the above by a, we get 4 - 2b/a + c/a =0, since -b/2a = 1, we got 8 + c/a = 0, so c/a = -8
3. The generic solution for the quadratic equation ax^2 + bx + c = 0 can be given by

-b/2a +/- sqrt((b/2a)^2 - c/a) = 1 +/- sqrt( 1 +8) = 1 +/- 3

1. So the solution is x=-2, or x=4