Subtract 21/27 from 20/84
20/84 - 21/27 is -34/63.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 84 and 27 is 756
Next, find the equivalent fraction of both fractional numbers with denominator 756 - For the 1st fraction, since 84 × 9 = 756,
20/84 = 20 × 9/84 × 9 = 180/756 - Likewise, for the 2nd fraction, since 27 × 28 = 756,
21/27 = 21 × 28/27 × 28 = 588/756 - Subtract the two like fractions:
180/756 - 588/756 = 180 - 588/756 = -408/756 - After reducing the fraction, the answer is -34/63
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