m/m2-1 * m2+2m-3/my
Altho this is an algebra question (with three very good answers given above), I'd like to add a "test-prep" tip, especially for so-called "standardized" tests, such as the SAT:
Once you have factored one polynomial, don't start all over to factor the other one.
Instead, begin by looking for one of the SAME terms as a factor.
Since the SAT weights all questions the same, and since there is much time pressure (e.g. 20 questions in 25 minutes), no one question should consume much more than one minute, so there will ALWAYS have to be some cancellation on SAT questions like this.
Please note that "test-prep" techniques should NOT be blindly applied in school; they can backfire badly on real tests prepared by a teacher or professor (where your work counts, almost-correct answers are a plus not a minus, and good math problems are rarely "multiple choice")! I always warn my "test-prep" students that "I'll be giving you lots of BAD advice" -- use these "test-prep" techniques only for "standardized" tests like the SAT; don't use them on school tests!