Subtract 21/81 from 18/40
18/40 - 21/81 is 103/540.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 81 is 3240
Next, find the equivalent fraction of both fractional numbers with denominator 3240 - For the 1st fraction, since 40 × 81 = 3240,
18/40 = 18 × 81/40 × 81 = 1458/3240 - Likewise, for the 2nd fraction, since 81 × 40 = 3240,
21/81 = 21 × 40/81 × 40 = 840/3240 - Subtract the two like fractions:
1458/3240 - 840/3240 = 1458 - 840/3240 = 618/3240 - After reducing the fraction, the answer is 103/540
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