Verified answer

x^2 + 4x + 3 = 0

(x^2 + 4x) + 3 = 0

(x + 2)^2 - (2)^2 + 3 = 0

(x + 2)^2 - 1 = 0

(x + 2)^2 = 1

x + 2 = 1 or x + 2 = -1

x = -1 or x = -3

Answer:

The answer is - -1 upon 2.