Subtract 20/54 from 4/21
4/21 - 20/54 is -34/189.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 54 is 378
Next, find the equivalent fraction of both fractional numbers with denominator 378 - For the 1st fraction, since 21 × 18 = 378,
4/21 = 4 × 18/21 × 18 = 72/378 - Likewise, for the 2nd fraction, since 54 × 7 = 378,
20/54 = 20 × 7/54 × 7 = 140/378 - Subtract the two like fractions:
72/378 - 140/378 = 72 - 140/378 = -68/378 - After reducing the fraction, the answer is -34/189
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