Question 86131
x^2 + 2x - 15 = 0

==> x^2 + 5x - 3x - 15 = 0

==> x(x+5) - 3(x+5)= 0

==> (x+5)(x-3) = 0

==> x+5=0  or x-3 = 0

==> x = -5  or x = 3