Subtract 28/21 from 7/40
1st number: 7/40, 2nd number: 1 7/21
7/40 - 28/21 is -139/120.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 21 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 40 × 21 = 840,
7/40 = 7 × 21/40 × 21 = 147/840 - Likewise, for the 2nd fraction, since 21 × 40 = 840,
28/21 = 28 × 40/21 × 40 = 1120/840 - Subtract the two like fractions:
147/840 - 1120/840 = 147 - 1120/840 = -973/840 - After reducing the fraction, the answer is -139/120
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