Question

Solve this quadratic equation by completing the square.

x² + 8x= 10
A. X=-4+ /26
B. x= -8 + /26
C. X= -8 + /10
D. x = -4 +/10​

Answer 1

A. x = -4 +/-√26.

Explanation:

x^2 + 8x = 10

using the completing the square identity:

x^2 + ax = (x + a/2)^2 - (a/2)^2 :

(x + 4)^2 - 4^2 = 10

(x + 4)^2 = 26

x + 4 = ± √26

x = -4 +/-√26.