Subtract 21/20 from 15/28
1st number: 15/28, 2nd number: 1 1/20
15/28 - 21/20 is -18/35.
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,
15/28 = 15 × 5/28 × 5 = 75/140 - Likewise, for the 2nd fraction, since 20 × 7 = 140,
21/20 = 21 × 7/20 × 7 = 147/140 - Subtract the two like fractions:
75/140 - 147/140 = 75 - 147/140 = -72/140 - After reducing the fraction, the answer is -18/35
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