Subtract 15/28 from 21/40
21/40 - 15/28 is -3/280.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 28 is 280
Next, find the equivalent fraction of both fractional numbers with denominator 280 - For the 1st fraction, since 40 × 7 = 280,
21/40 = 21 × 7/40 × 7 = 147/280 - Likewise, for the 2nd fraction, since 28 × 10 = 280,
15/28 = 15 × 10/28 × 10 = 150/280 - Subtract the two like fractions:
147/280 - 150/280 = 147 - 150/280 = -3/280
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