Subtract 20/40 from 3/7
3/7 - 20/40 is -1/14.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 7 and 40 is 280
Next, find the equivalent fraction of both fractional numbers with denominator 280 - For the 1st fraction, since 7 × 40 = 280,
3/7 = 3 × 40/7 × 40 = 120/280 - Likewise, for the 2nd fraction, since 40 × 7 = 280,
20/40 = 20 × 7/40 × 7 = 140/280 - Subtract the two like fractions:
120/280 - 140/280 = 120 - 140/280 = -20/280 - After reducing the fraction, the answer is -1/14
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