Add 21/18 and 18/21
1st number: 1 3/18, 2nd number: 18/21
21/18 + 18/21 is 85/42.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 21 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 18 × 7 = 126,
21/18 = 21 × 7/18 × 7 = 147/126 - Likewise, for the 2nd fraction, since 21 × 6 = 126,
18/21 = 18 × 6/21 × 6 = 108/126 - Add the two like fractions:
147/126 + 108/126 = 147 + 108/126 = 255/126 - 255/126 simplified gives 85/42
- So, 21/18 + 18/21 = 85/42
In mixed form: 21/42
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