Question

#4: Solve the quadratic equation below by completing the square. Select

Answer 1

Answer:

x = - 13, x = - 3

Step-by-step explanation:

Given

x² + 16x = - 39

To complete the square

add ( half the coefficient of the x- term )² to both sides

x² + 2(8)x + 64 = - 39 + 64

(x + 8)² = 25 ( take the square root of both sides )

x + 8 = ± $\sqrt{25}$ = ± 5 ( subtract 8 from both sides )

x = - 8 ± 5, thus

x = - 8 - 5 = - 13 or x = - 8 + 5 = - 3