Answer:
x^3 -3x^2 -13x +15
Explanation:
The LCM is the product of unique factors, so the first step is to find the factors of each expression.
x^2 -2x -15 = (x -5)(x +3)
x^2 +2x -3) = (x -1)(x +3)
The unique factors are (x -5), (x +3), (x -1). The LCM is their product, which we can compute by multiplying the first expression by the factor it does not contain:
LCM( ) = (x -1)(x^2 -2x -15) = x^3 -3x^2 -13x +15