SOLUTION: Explain the error in the following: x^2 + 2x

SOLUTION: Explain the error in the following: x^2 + 2x - 15 = (x-5)(x+3)

Question 315874: Explain the error in the following:
x^2 + 2x - 15 = (x-5)(x+3)
Answer by mananth(16949) (Show Source): You can put this solution on YOUR website!
x^2+2x-15
x^2+5x-3x-15
x(x+5)-3(x+5)
(x-3)(x+5)