Subtract 70/21 from 70/54, Solve 1 16/54

Subtract 70/21 from 70/54

1^st number: 1 16/54, 2^nd number: 3 7/21

70/54 - 70/21 is -55/27.

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,
70/54 = 70 × 7/54 × 7 = 490/378
Likewise, for the 2nd fraction, since 21 × 18 = 378,
70/21 = 70 × 18/21 × 18 = 1260/378
Subtract the two like fractions:
490/378 - 1260/378 = 490 - 1260/378 = -770/378
After reducing the fraction, the answer is -55/27

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