Subtract 27/21 from 40/54, Solve 40/54

Subtract 27/21 from 40/54

1^st number: 40/54, 2^nd number: 1 6/21

40/54 - 27/21 is -103/189.

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,
40/54 = 40 × 7/54 × 7 = 280/378
Likewise, for the 2nd fraction, since 21 × 18 = 378,
27/21 = 27 × 18/21 × 18 = 486/378
Subtract the two like fractions:
280/378 - 486/378 = 280 - 486/378 = -206/378
After reducing the fraction, the answer is -103/189

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