Add 18/21 and 15/28
18/21 + 15/28 is 39/28.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 28 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 21 × 4 = 84,
18/21 = 18 × 4/21 × 4 = 72/84 - Likewise, for the 2nd fraction, since 28 × 3 = 84,
15/28 = 15 × 3/28 × 3 = 45/84 - Add the two like fractions:
72/84 + 45/84 = 72 + 45/84 = 117/84 - 117/84 simplified gives 39/28
- So, 18/21 + 15/28 = 39/28
In mixed form: 111/28
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