Subtract 15/54 from 10/42, Solve 10/42

Subtract 15/54 from 10/42

10/42 - 15/54 is -5/126.

Find the least common denominator or LCM of the two denominators:
LCM of 42 and 54 is 378

Next, find the equivalent fraction of both fractional numbers with denominator 378
For the 1st fraction, since 42 × 9 = 378,
10/42 = 10 × 9/42 × 9 = 90/378
Likewise, for the 2nd fraction, since 54 × 7 = 378,
15/54 = 15 × 7/54 × 7 = 105/378
Subtract the two like fractions:
90/378 - 105/378 = 90 - 105/378 = -15/378
After reducing the fraction, the answer is -5/126

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