Subtract 18/27 from 3/42, Solve 3/42

Subtract 18/27 from 3/42

3/42 - 18/27 is -25/42.

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,
3/42 = 3 × 9/42 × 9 = 27/378
Likewise, for the 2nd fraction, since 27 × 14 = 378,
18/27 = 18 × 14/27 × 14 = 252/378
Subtract the two like fractions:
27/378 - 252/378 = 27 - 252/378 = -225/378
After reducing the fraction, the answer is -25/42

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