Subtract 21/28 from 18/30
18/30 - 21/28 is -3/20.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 28 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 30 × 14 = 420,
18/30 = 18 × 14/30 × 14 = 252/420 - Likewise, for the 2nd fraction, since 28 × 15 = 420,
21/28 = 21 × 15/28 × 15 = 315/420 - Subtract the two like fractions:
252/420 - 315/420 = 252 - 315/420 = -63/420 - After reducing the fraction, the answer is -3/20
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