Subtract 1/40 from 21/81
21/81 - 1/40 is 253/1080.
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,
21/81 = 21 × 40/81 × 40 = 840/3240 - Likewise, for the 2nd fraction, since 40 × 81 = 3240,
1/40 = 1 × 81/40 × 81 = 81/3240 - Subtract the two like fractions:
840/3240 - 81/3240 = 840 - 81/3240 = 759/3240 - After reducing the fraction, the answer is 253/1080
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