Add 81/84 and 21/40
81/84 + 21/40 is 417/280.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 84 and 40 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 84 × 10 = 840,
81/84 = 81 × 10/84 × 10 = 810/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
21/40 = 21 × 21/40 × 21 = 441/840 - Add the two like fractions:
810/840 + 441/840 = 810 + 441/840 = 1251/840 - 1251/840 simplified gives 417/280
- So, 81/84 + 21/40 = 417/280
In mixed form: 1137/280
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