Subtract 70/54 from 42/21, Solve 2 0/21

Subtract 70/54 from 42/21

1^st number: 2 0/21, 2^nd number: 1 16/54

42/21 - 70/54 is 19/27.

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

Next, find the equivalent fraction of both fractional numbers with denominator 378
For the 1st fraction, since 21 × 18 = 378,
42/21 = 42 × 18/21 × 18 = 756/378
Likewise, for the 2nd fraction, since 54 × 7 = 378,
70/54 = 70 × 7/54 × 7 = 490/378
Subtract the two like fractions:
756/378 - 490/378 = 756 - 490/378 = 266/378
After reducing the fraction, the answer is 19/27

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