Example 1: Find the value of 19 + 37 + 521 + 23
The lowest common multiple is 63. The several denominators, when divided into 63, give 7, 9, 3, 21 respectively, for quotients. Therefore, we multiply the numerators and denominators of the fractions by 7, 9, 3, 21, and add the numerators to obtain the required sum. The result must be reduced to a mixed number or to lower terms, if necessary.
Work: 19 + 37 + 521 + 23 = 7 + 27 + 15 + 4263 = 91⁄63 = 128⁄63 = 14⁄9 Ans.
In adding mixed numbers, first add the whole numbers, then the fractions, finally adding the two results.
Example 2: Add together 31⁄8 + 7⁄24 + 711⁄15 + 43⁄20. Given expression:
= 3 + 7 + 4 + 18 + 724 + 1115 + 320
= 14 + 15 + 35 + 88 + 18120
= 14 + 156120 = 14 + 136120 = 15310 Ans.