Answer:
x = 3 or x = - 6
Step-by-step explanation:
Factor and Solve. x^2 + 3x - 18 = 0
We can use the Diamond method of factoring.
Factor -18 = 6 * -3; and 3 = 6 + -3
so
x^2 + 3x - 18 = x^2 -3x + 6x - 18 = 0
= (x^2 -3x) + ( 6x - 18) = 0
= (x^2 -3x) + ( 6x - 18) = 0
= x(x - 3) + 6*(x - 3) =0
= (x - 3)*(x + 6) = 0
so Either x - 3 = 0 or x + 6 = 0
x = 3 or x = - 6