Solve by completing the square,

Question

8x^2+4x-4=0

Answer 1

divide by 8 and re-arrange
x^2 + (1/2)x = 1/2
x^2 + (1/2)x + 1/16 = 1/2 + 1/16
(x + 1/4)^2 = 9/16
x + 1/4 = ± 3/4
x = -1/4 ± 3/4
= 1/2 or -1

Answer 2

Reiny,

Im sorry but where is the 1/16 coming from?

Answer 3

take half of the middle coefficient , the square it

1/2 of 1/2 is 1/4
1/4 squared is 1/16

I added that to both sides, thus not changing the value of my equation.