Subtract 15/16 from 21/40
21/40 - 15/16 is -33/80.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 16 is 80
Next, find the equivalent fraction of both fractional numbers with denominator 80 - For the 1st fraction, since 40 × 2 = 80,
21/40 = 21 × 2/40 × 2 = 42/80 - Likewise, for the 2nd fraction, since 16 × 5 = 80,
15/16 = 15 × 5/16 × 5 = 75/80 - Subtract the two like fractions:
42/80 - 75/80 = 42 - 75/80 = -33/80
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