First off, these fractions will work to your advantage if they are in the form of an improper fraction. 7 and 3/4 as an improper fraction is 31/4. 2 and 1/3 as an improper fraction is 7/3. Now, in order to add and subtract fractions, they need to have a common denominator. 3 and 4 share a common multiple of 12. 31/4 = 93/12. (You need to multiply by the same number in the numerator as you did in the denominator. Multiply 4 by 3 to get 12. Multiply 31 by 3 to get the new numerator.) 7/3 = 28/12 (Multiply by 4 to get 12 in the denominator. Multiply 4 by 7 for the numerator.) 93/12 -28/12 = 65/12 This fraction can also be expressed as a mixed number. 5 and 5/12.
