Subtract 21/20 from 28/42
1st number: 28/42, 2nd number: 1 1/20
28/42 - 21/20 is -23/60.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 20 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 42 × 10 = 420,
28/42 = 28 × 10/42 × 10 = 280/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
21/20 = 21 × 21/20 × 21 = 441/420 - Subtract the two like fractions:
280/420 - 441/420 = 280 - 441/420 = -161/420 - After reducing the fraction, the answer is -23/60
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