Subtract 21/40 from 7/15
7/15 - 21/40 is -7/120.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 15 and 40 is 120
Next, find the equivalent fraction of both fractional numbers with denominator 120 - For the 1st fraction, since 15 × 8 = 120,
7/15 = 7 × 8/15 × 8 = 56/120 - Likewise, for the 2nd fraction, since 40 × 3 = 120,
21/40 = 21 × 3/40 × 3 = 63/120 - Subtract the two like fractions:
56/120 - 63/120 = 56 - 63/120 = -7/120
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