Add 21/84 and 81/90
21/84 + 81/90 is 23/20.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 84 and 90 is 1260
Next, find the equivalent fraction of both fractional numbers with denominator 1260 - For the 1st fraction, since 84 × 15 = 1260,
21/84 = 21 × 15/84 × 15 = 315/1260 - Likewise, for the 2nd fraction, since 90 × 14 = 1260,
81/90 = 81 × 14/90 × 14 = 1134/1260 - Add the two like fractions:
315/1260 + 1134/1260 = 315 + 1134/1260 = 1449/1260 - 1449/1260 simplified gives 23/20
- So, 21/84 + 81/90 = 23/20
In mixed form: 13/20
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