Subtract 14/18 from 21/7, Solve 3 0/7

Subtract 14/18 from 21/7

1^st number: 3 0/7, 2^nd number: 14/18

21/7 - 14/18 is 20/9.

Find the least common denominator or LCM of the two denominators:
LCM of 7 and 18 is 126

Next, find the equivalent fraction of both fractional numbers with denominator 126
For the 1st fraction, since 7 × 18 = 126,
21/7 = 21 × 18/7 × 18 = 378/126
Likewise, for the 2nd fraction, since 18 × 7 = 126,
14/18 = 14 × 7/18 × 7 = 98/126
Subtract the two like fractions:
378/126 - 98/126 = 378 - 98/126 = 280/126
After reducing the fraction, the answer is 20/9
In mixed form: 22/9

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