The least common multiple of the polynomials given above can be obtained by multiplying the factors of each, being careful that non of the factors will be repeated.
9(x + 2)(2x - 1) = (3)(3)(x + 2)(2x - 1)
3(x + 2) = 3(x + 2)
LCM = (3)(3)(x + 2)(2x - 1)
