Question

What is the intermediate step in the form (x + a)? = b as a result of completing the

square for the following equation?
x2 + 18x + 57 = 12

Answer 1

(x + 9)² = 36

Explanation:

Given

x² + 18x + 57 = 12 ( subtract 57 from both sides )

x² + 18x = - 45

To complete the square

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

x² + 2(9)x + 81 = - 45 + 81

(x + 9)² = 36