Subtract 81/21 from 40/28
1st number: 1 12/28, 2nd number: 3 18/21
40/28 - 81/21 is -17/7.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 28 and 21 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 28 × 3 = 84,
40/28 = 40 × 3/28 × 3 = 120/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
81/21 = 81 × 4/21 × 4 = 324/84 - Subtract the two like fractions:
120/84 - 324/84 = 120 - 324/84 = -204/84 - After reducing the fraction, the answer is -17/7
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