Question

Select the correct answer. Solve the equation by completing the square. 0 = x2 − 14x A. x = 0, 14 B. x = -56, 42 C. x = -42, 56 D. x = -14, 0

Answer 1

A

Explanation:

Given

x² - 14x = 0

To complete the square

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

x² + 2(- 7)x + 49 = 0 + 49

(x - 7)² = 49 ( take the square root of both sides )

x - 7 = ±
`√(49)` = ± 7 ( add 7 to both sides )

x = 7 ± 7 , thus

x = 7 + 7 = 14 or x = 7 - 7 = 0