Question

X^2+6x+8=0 complete the square method

Answer 1

x = - 2 or x = - 4

Explanation:

Via completing the square:

x^2 + 6x + 8 = x^2 + 6x + (6/2)^2 - (6/2)^2 + 8

= (x + 3)^2 - 3^2 + 8

= (x + 3)^2 - 9 + 8

= (x + 3)^2 - 1

Since x^2+6x+8=0,

(x + 3)^2 - 1 = 0

(x + 3)^2 = 1

x + 3 = +- sqrt(1)

x + 3 = +- 1

x + 3 = 1 or x + 3 = -1

x = -2 or x = -4