Subtract 21/56 from 5/42
5/42 - 21/56 is -43/168.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 56 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 42 × 4 = 168,
5/42 = 5 × 4/42 × 4 = 20/168 - Likewise, for the 2nd fraction, since 56 × 3 = 168,
21/56 = 21 × 3/56 × 3 = 63/168 - Subtract the two like fractions:
20/168 - 63/168 = 20 - 63/168 = -43/168
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