## Precalculus: Concepts Through Functions, A Unit Circle Approach to Trigonometry (3rd Edition)

$(x-2)(x+2)(x+1)$
To find the least common multiple (LCM), we factor the polynomials completely and the LCM is the product of each of these factors raised to the greatest power that occurs in the polynomials. So, we have $$x^2 - 4=(x-2)(x+2), \quad x^2 - x - 2=(x-2)(x+1) .$$ Thus, the LCM is $(x-2)(x+2)(x+1)$.