Subtract 27/28 from 9/21
9/21 - 27/28 is -15/28.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 28 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 21 × 4 = 84,
9/21 = 9 × 4/21 × 4 = 36/84 - Likewise, for the 2nd fraction, since 28 × 3 = 84,
27/28 = 27 × 3/28 × 3 = 81/84 - Subtract the two like fractions:
36/84 - 81/84 = 36 - 81/84 = -45/84 - After reducing the fraction, the answer is -15/28
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