Add 15/21 and 3/7
15/21 + 3/7 is 8/7.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 7 is 21
Next, find the equivalent fraction of both fractional numbers with denominator 21 - For the 1st fraction, since 21 × 1 = 21,
15/21 = 15 × 1/21 × 1 = 15/21 - Likewise, for the 2nd fraction, since 7 × 3 = 21,
3/7 = 3 × 3/7 × 3 = 9/21 - Add the two like fractions:
15/21 + 9/21 = 15 + 9/21 = 24/21 - 24/21 simplified gives 8/7
- So, 15/21 + 3/7 = 8/7
In mixed form: 11/7
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