Subtract 21/15 from 20/40
1st number: 20/40, 2nd number: 1 6/15
20/40 - 21/15 is -9/10.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 15 is 120
Next, find the equivalent fraction of both fractional numbers with denominator 120 - For the 1st fraction, since 40 × 3 = 120,
20/40 = 20 × 3/40 × 3 = 60/120 - Likewise, for the 2nd fraction, since 15 × 8 = 120,
21/15 = 21 × 8/15 × 8 = 168/120 - Subtract the two like fractions:
60/120 - 168/120 = 60 - 168/120 = -108/120 - After reducing the fraction, the answer is -9/10
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