First we must convert both mixed numbers into Improper fractions. To do this, multiply the denominator by its whole number and add the numerator. For example in 3 3/4, multiply 3 and 4 and add 3. Your mixed number is 15/4. For 2 1/2, your mixed number is 5/2. Then, you multiply the numerators by each other and the denominators by each other, so 15(5) / 4(2) to get 75/8 or 9 3/8.
