Question

factor this equation. x squared -9x-36=0. show work

Answer 1

x^2 - 9x - 36 = 0


x^2 - 12x + 3x - 36 = 0


(x^2 - 12x) + (3x - 36) = 0


x(x - 12) + 3(x - 12) = 0


(x + 3)(x - 12) = 0


x + 3 = 0 or x - 12 = 0


x = -3 or x = 12

Answer 2

Take note that the two numbers -12 and 3 both multiply to -36 and add to -9.