Add 15/21 and 18/42
15/21 + 18/42 is 8/7.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 42 is 42
Next, find the equivalent fraction of both fractional numbers with denominator 42 - For the 1st fraction, since 21 × 2 = 42,
15/21 = 15 × 2/21 × 2 = 30/42 - Likewise, for the 2nd fraction, since 42 × 1 = 42,
18/42 = 18 × 1/42 × 1 = 18/42 - Add the two like fractions:
30/42 + 18/42 = 30 + 18/42 = 48/42 - 48/42 simplified gives 8/7
- So, 15/21 + 18/42 = 8/7
In mixed form: 11/7
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