Subtract 4/5 from 21/40
21/40 - 4/5 is -11/40.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 5 is 40
Next, find the equivalent fraction of both fractional numbers with denominator 40 - For the 1st fraction, since 40 × 1 = 40,
21/40 = 21 × 1/40 × 1 = 21/40 - Likewise, for the 2nd fraction, since 5 × 8 = 40,
4/5 = 4 × 8/5 × 8 = 32/40 - Subtract the two like fractions:
21/40 - 32/40 = 21 - 32/40 = -11/40
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