ebony is solving a quadratic equation. she wants to find the value of x by taking the square root of both sides of the equation. which equation allows her to do this?

a. x^2 - 8x + 64 = 32

b. x^2 - 144x + 12 = 13

c. x^2 - 6x - 9 = 15

d. x^2 - 4x + 4 = 36