Find the roots of the quadratic equation: x2 + 2x – 15 = 0?

A. -5, 3
B. 3, 5
C. -3, 5
D. -3, -5

Explanation:

x2 + 5x – 3x – 15 = 0
x(x + 5) – 3(x + 5) = 0
(x – 3)(x + 5) = 0
=> x = 3 or x = -5.