Subtract 81/7 from 12/21
1st number: 12/21, 2nd number: 11 4/7
12/21 - 81/7 is -11/1.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 7 is 21
Next, find the equivalent fraction of both fractional numbers with denominator 21 - For the 1st fraction, since 21 × 1 = 21,
12/21 = 12 × 1/21 × 1 = 12/21 - Likewise, for the 2nd fraction, since 7 × 3 = 21,
81/7 = 81 × 3/7 × 3 = 243/21 - Subtract the two like fractions:
12/21 - 243/21 = 12 - 243/21 = -231/21 - After reducing the fraction, the answer is -11/1
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