Easiest way to solve it is to cross off factors that appear in the numerator and denominator. For example, we can divide both the 12 and the 8 by 4:
Then perhaps cancel the 2's out
as well as a factor of 3 (3 becomes 1, 9 becomes 3)
Multiplying, our answer is -5/33.
Of course, there are a trillion different ways one could multiply it out, depending on the order one chooses to cancel out factors from the numerator or denominator...you could even multiply first, then cancel everything out (this can get time-consuming, though).
