Subtract 81/7 from 21/20
1st number: 1 1/20, 2nd number: 11 4/7
21/20 - 81/7 is -1473/140.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 7 is 140
Next, find the equivalent fraction of both fractional numbers with denominator 140 - For the 1st fraction, since 20 × 7 = 140,
21/20 = 21 × 7/20 × 7 = 147/140 - Likewise, for the 2nd fraction, since 7 × 20 = 140,
81/7 = 81 × 20/7 × 20 = 1620/140 - Subtract the two like fractions:
147/140 - 1620/140 = 147 - 1620/140 = -1473/140
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