Solve: x^2 + x - 12 = 0

x² + x - 12 = 0/ x² + 4x - 3x - 12 = 0 (split x into two numbers which multiply to equal -12)/ x(x + 4) - 3(x + 4) = 0 (take out x and 3 respectively)/ (x + 4)(x - 3) = 0 (collect terms)/ x = -4, x = 3