Subtract 21/20 from 18/28
1st number: 18/28, 2nd number: 1 1/20
18/28 - 21/20 is -57/140.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 28 and 20 is 140
Next, find the equivalent fraction of both fractional numbers with denominator 140 - For the 1st fraction, since 28 × 5 = 140,
18/28 = 18 × 5/28 × 5 = 90/140 - Likewise, for the 2nd fraction, since 20 × 7 = 140,
21/20 = 21 × 7/20 × 7 = 147/140 - Subtract the two like fractions:
90/140 - 147/140 = 90 - 147/140 = -57/140
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