Question

Find the least common multiple of
x^2 +x-12 and x^2 +2x-15

Answer 1

first factor each trinomial

Answer 2

(x+4)(x-3) and (x+5)(x-3)

Answer 3

Now that we have factored both equations, what are the common factors for both equations?
(x - 3) is common to both
So we include it in the LCM

Next, what are the un-common factors for both equations?
(x + 4) appears in the first but not in the second
(x + 5) appears in the second but not in the first
So we include both in the LCM as multipliers

Therefore, the LCM for this problem is:
(x - 3)(x + 4)(x + 5)

Answer 4

Since (x-3) are the same don't they count as being written only once? Like (x+4)(x-3)(x+5)?