Subtract 18/15 from 21/28
1st number: 21/28, 2nd number: 1 3/15
21/28 - 18/15 is -9/20.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 28 and 15 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 28 × 15 = 420,
21/28 = 21 × 15/28 × 15 = 315/420 - Likewise, for the 2nd fraction, since 15 × 28 = 420,
18/15 = 18 × 28/15 × 28 = 504/420 - Subtract the two like fractions:
315/420 - 504/420 = 315 - 504/420 = -189/420 - After reducing the fraction, the answer is -9/20
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