Subtract 8/21 from 72/54, Solve 1 18/54

Subtract 8/21 from 72/54

1^st number: 1 18/54, 2^nd number: 8/21

72/54 - 8/21 is 20/21.

Find the least common denominator or LCM of the two denominators:
LCM of 54 and 21 is 378

Next, find the equivalent fraction of both fractional numbers with denominator 378
For the 1st fraction, since 54 × 7 = 378,
72/54 = 72 × 7/54 × 7 = 504/378
Likewise, for the 2nd fraction, since 21 × 18 = 378,
8/21 = 8 × 18/21 × 18 = 144/378
Subtract the two like fractions:
504/378 - 144/378 = 504 - 144/378 = 360/378
After reducing the fraction, the answer is 20/21

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