Step 1. Factor x^2 - 2x - 15
(x - 5)(x + 3)/x^2 + 4x + 3
Step 2. Factor x^2 + 4x + 3
(x - 5)(x + 3)/(x + 1)(x + 3)
Step 3. Cancel x + 3
x - 5/x + 1
