Review of Introductory Mathematics FRACTIONS Comparing this list to the others, the denominators of 3, 12, and 6 can all be calculated from the list, but 7 cannot be, so a 7 must be included in the list. 2 x 2 x 3 x 7 = 84 Step 3: Rewrite the equation 1 7 12 12 2 3 28 28 11 12 7 7 4 6 14 14 Step 4: Add 12 84 56 84 77 84 56 84 201 84 Addition and Subtraction Denominators of fractions being added or subtracted must be the same. The resulting sum or difference is then the sum or difference of the numerators of the fractions being added or subtracted. Examples: = = 1 2 3 1 3 2 1 3 = = 4 7 1 7 4 1 7 5 7 = = 4 9 2 9 4 2 9 2 9 = = 8 11 2 11 5 11 8 2 5 11 1 11 Rev. 0 Page 33 MA-01