Subtract 28/21 from 15/20
1st number: 15/20, 2nd number: 1 7/21
15/20 - 28/21 is -7/12.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 21 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 20 × 21 = 420,
15/20 = 15 × 21/20 × 21 = 315/420 - Likewise, for the 2nd fraction, since 21 × 20 = 420,
28/21 = 28 × 20/21 × 20 = 560/420 - Subtract the two like fractions:
315/420 - 560/420 = 315 - 560/420 = -245/420 - After reducing the fraction, the answer is -7/12
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