Solve the equation by completing the square. 0 = 4x2 - 72x A. x = 0, 18 B. x = - 72, 90 C. x = - 90, 72 D. x = - 18, 0

x^2 - 18x + 81 = 81

(x - 9) ^2 = 81

Step-by-step explanation:

0 = 4x^2 - 72x

4x^2 - 72x = 0

x^2 - 18x = 0

x^2 - 18x + 81 = 81

(x - 9) ^2 = 81

A. x = 0, 18

Step-by-step explanation:

Step 1: GCF

4 (x² - 18x) = 0

x² - 18x = 0

Step 2: Complete the Square

x² - 18x + 81 = 0 + 81

(x - 9) ² = 81

Step 3: Solve

√ (x - 9) ² = √81

x - 9 = ±9

x = 9±9, or x = 0, 18

And we have our answers!