Add 21/28 and 12/15
21/28 + 12/15 is 31/20.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 28 and 15 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 28 × 15 = 420,
21/28 = 21 × 15/28 × 15 = 315/420 - Likewise, for the 2nd fraction, since 15 × 28 = 420,
12/15 = 12 × 28/15 × 28 = 336/420 - Add the two like fractions:
315/420 + 336/420 = 315 + 336/420 = 651/420 - 651/420 simplified gives 31/20
- So, 21/28 + 12/15 = 31/20
In mixed form: 111/20
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