Question

What equation results from completing the square and then factoring? x^2 +4x=5

A. (x+2)^2 =9

B. (x+2)^2 =3

C. (x+2)^2 =7

D. (x+2)^2 =1

Answer 1

A. (x+2)^2 = 9

Explanation:

To complete the square, you add the square of half the x-coefficient.

... x^2 +4x +(4/2)^2 = 5 + (4/2)^2

... x^2 +4x +4 = 9

Factoring gives you ...

... (x +2)^2 = 9 . . . . . . matches selection A