Question

Which are steps that could be used to solve 0 = 9(x2 6x) – 18 by completing the square? Check all that apply. 18 81 = 9(x2 6x 9) 18 9 = 9(x2 6x 9) 18 36 = 9(x2 6x 36) 11 = (x 3)2 StartRoot 342 EndRoot = (x 6)2 StartRoot 99 EndRoot = (x 3)2

Answer 1

Answer:

18 + 81 = 9(x² + 6x + 9) 11 = (x + 3)²

Explanation:

because  This is the value that completes the square. However, since the entire square is multiplied by 9, this value must be multiplied by 9 before we can add it across the equals:

18 + 9 (9) = 9 (x² + 6x + 9)

18 + 81 = 9 (x² + 6x + 9)

99 = 9 (x² + 6x + 9)

Dividing both sides by 9, we have:

11 = x² + 6x + 9

11 = (x + 3) ²