Subtract 15/40 from 21/80
21/80 - 15/40 is -9/80.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 80 and 40 is 80
Next, find the equivalent fraction of both fractional numbers with denominator 80 - For the 1st fraction, since 80 × 1 = 80,
21/80 = 21 × 1/80 × 1 = 21/80 - Likewise, for the 2nd fraction, since 40 × 2 = 80,
15/40 = 15 × 2/40 × 2 = 30/80 - Subtract the two like fractions:
21/80 - 30/80 = 21 - 30/80 = -9/80
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