Add 21/84 and 54/15
1st number: 21/84, 2nd number: 3 9/15
21/84 + 54/15 is 77/20.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 84 and 15 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 84 × 5 = 420,
21/84 = 21 × 5/84 × 5 = 105/420 - Likewise, for the 2nd fraction, since 15 × 28 = 420,
54/15 = 54 × 28/15 × 28 = 1512/420 - Add the two like fractions:
105/420 + 1512/420 = 105 + 1512/420 = 1617/420 - 1617/420 simplified gives 77/20
- So, 21/84 + 54/15 = 77/20
In mixed form: 317/20
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