Subtract 20/27 from 15/21
15/21 - 20/27 is -5/189.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 27 is 189
Next, find the equivalent fraction of both fractional numbers with denominator 189 - For the 1st fraction, since 21 × 9 = 189,
15/21 = 15 × 9/21 × 9 = 135/189 - Likewise, for the 2nd fraction, since 27 × 7 = 189,
20/27 = 20 × 7/27 × 7 = 140/189 - Subtract the two like fractions:
135/189 - 140/189 = 135 - 140/189 = -5/189
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