Start with x^2 + 4x = 12 and complete the square, what is the equivalent equation?
A) (x + 2)^2 = 16
B) (x + 2)^2 = 14
C) (x + 4)^2 = 16
D) (x + 4)^2 = 28
The answer is A. You multiply each side by (b/2)^2. B is 4. 4 divided by 2 squared is 4. To make it the same equation squared, you factor it to (x+2)^2. You have to also add the (b/2)^2 to 12 so 12+4=16
