Subtract 21/27 from 21/28
21/28 - 21/27 is -1/36.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 28 and 27 is 756
Next, find the equivalent fraction of both fractional numbers with denominator 756 - For the 1st fraction, since 28 × 27 = 756,
21/28 = 21 × 27/28 × 27 = 567/756 - Likewise, for the 2nd fraction, since 27 × 28 = 756,
21/27 = 21 × 28/27 × 28 = 588/756 - Subtract the two like fractions:
567/756 - 588/756 = 567 - 588/756 = -21/756 - After reducing the fraction, the answer is -1/36
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