Subtract 3/7 from 21/81
21/81 - 3/7 is -32/189.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 7 is 567
Next, find the equivalent fraction of both fractional numbers with denominator 567 - For the 1st fraction, since 81 × 7 = 567,
21/81 = 21 × 7/81 × 7 = 147/567 - Likewise, for the 2nd fraction, since 7 × 81 = 567,
3/7 = 3 × 81/7 × 81 = 243/567 - Subtract the two like fractions:
147/567 - 243/567 = 147 - 243/567 = -96/567 - After reducing the fraction, the answer is -32/189
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