Subtract 21/20 from 18/84
1st number: 18/84, 2nd number: 1 1/20
18/84 - 21/20 is -117/140.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 84 and 20 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 84 × 5 = 420,
18/84 = 18 × 5/84 × 5 = 90/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
21/20 = 21 × 21/20 × 21 = 441/420 - Subtract the two like fractions:
90/420 - 441/420 = 90 - 441/420 = -351/420 - After reducing the fraction, the answer is -117/140
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