Subtract 21/7 from 21/40
1st number: 21/40, 2nd number: 3 0/7
21/40 - 21/7 is -99/40.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 7 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 7 × 40 = 280,
21/7 = 21 × 40/7 × 40 = 840/280 - Subtract the two like fractions:
147/280 - 840/280 = 147 - 840/280 = -693/280 - After reducing the fraction, the answer is -99/40
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