Subtract 28/27 from 7/42, Solve 7/42

Subtract 28/27 from 7/42

1^st number: 7/42, 2^nd number: 1 1/27

7/42 - 28/27 is -47/54.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 27 is 378

Next, find the equivalent fraction of both fractional numbers with denominator 378
For the 1st fraction, since 42 × 9 = 378,
7/42 = 7 × 9/42 × 9 = 63/378
Likewise, for the 2nd fraction, since 27 × 14 = 378,
28/27 = 28 × 14/27 × 14 = 392/378
Subtract the two like fractions:
63/378 - 392/378 = 63 - 392/378 = -329/378
After reducing the fraction, the answer is -47/54

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