Subtract 20/21 from 7/27
7/27 - 20/21 is -131/189.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 27 and 21 is 189
Next, find the equivalent fraction of both fractional numbers with denominator 189 - For the 1st fraction, since 27 × 7 = 189,
7/27 = 7 × 7/27 × 7 = 49/189 - Likewise, for the 2nd fraction, since 21 × 9 = 189,
20/21 = 20 × 9/21 × 9 = 180/189 - Subtract the two like fractions:
49/189 - 180/189 = 49 - 180/189 = -131/189
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