Subtract 21/40 from 40/81
40/81 - 21/40 is -101/3240.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 40 is 3240
Next, find the equivalent fraction of both fractional numbers with denominator 3240 - For the 1st fraction, since 81 × 40 = 3240,
40/81 = 40 × 40/81 × 40 = 1600/3240 - Likewise, for the 2nd fraction, since 40 × 81 = 3240,
21/40 = 21 × 81/40 × 81 = 1701/3240 - Subtract the two like fractions:
1600/3240 - 1701/3240 = 1600 - 1701/3240 = -101/3240
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