Subtract 56/12 from 81/21
1st number: 3 18/21, 2nd number: 4 8/12
81/21 - 56/12 is -17/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 12 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 21 × 4 = 84,
81/21 = 81 × 4/21 × 4 = 324/84 - Likewise, for the 2nd fraction, since 12 × 7 = 84,
56/12 = 56 × 7/12 × 7 = 392/84 - Subtract the two like fractions:
324/84 - 392/84 = 324 - 392/84 = -68/84 - After reducing the fraction, the answer is -17/21
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