Subtract 20/42 from 15/81
15/81 - 20/42 is -55/189.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 42 is 1134
Next, find the equivalent fraction of both fractional numbers with denominator 1134 - For the 1st fraction, since 81 × 14 = 1134,
15/81 = 15 × 14/81 × 14 = 210/1134 - Likewise, for the 2nd fraction, since 42 × 27 = 1134,
20/42 = 20 × 27/42 × 27 = 540/1134 - Subtract the two like fractions:
210/1134 - 540/1134 = 210 - 540/1134 = -330/1134 - After reducing the fraction, the answer is -55/189
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