Subtract 42/81 from 20/42
20/42 - 42/81 is -8/189.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 81 is 1134
Next, find the equivalent fraction of both fractional numbers with denominator 1134 - For the 1st fraction, since 42 × 27 = 1134,
20/42 = 20 × 27/42 × 27 = 540/1134 - Likewise, for the 2nd fraction, since 81 × 14 = 1134,
42/81 = 42 × 14/81 × 14 = 588/1134 - Subtract the two like fractions:
540/1134 - 588/1134 = 540 - 588/1134 = -48/1134 - After reducing the fraction, the answer is -8/189
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