Solve the given quadratic equation by completing the square.

$3x^2-6x-9=0$

CONCEPT PREVIEW Use choices A–D to answer each question.

A. 3x² - 17x - 6 = 0

B.(2x + 5)² = 7

C. x² + x = 12

D. (3x - 1) (x - 7) = 0

Which quadratic equation is set up for direct use of the square root property? Solve it.

Solve each quadratic equation using the zero-factor property. See Example 5.

x² + 2x - 8 = 0

Solve each quadratic equation using the zero-factor property. See Example 5.

9x² - 12x + 4 = 0

Solve each quadratic equation using the quadratic formula. See Example 7.

-3x² + 6x + 5 = 0

Solve each quadratic equation using the zero-factor property. See Example 5. 5x² - 3x - 2 = 0

Solve each quadratic equation using the zero-factor property. See Example 5. -4x² + x = -3

Solve each quadratic equation using the zero-factor property. See Example 5. x² - 100 = 0