First, we will change your 2 mixed numbers into improper fractions.
1 1/2 = 3/2
4 1/2 = 9/2
Next, we multiply the numerators and multiply the denominators
9*3 and 2*2, keeping the fraction form.
9*3=27 2*2=4 so we now have 27 over 4, the answer is 27/4, or 6 3/4
I hope that this helps, feel free to ask questions.