Subtract 42/63 from 20/81
20/81 - 42/63 is -34/81.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 63 is 567
Next, find the equivalent fraction of both fractional numbers with denominator 567 - For the 1st fraction, since 81 × 7 = 567,
20/81 = 20 × 7/81 × 7 = 140/567 - Likewise, for the 2nd fraction, since 63 × 9 = 567,
42/63 = 42 × 9/63 × 9 = 378/567 - Subtract the two like fractions:
140/567 - 378/567 = 140 - 378/567 = -238/567 - After reducing the fraction, the answer is -34/81
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