Subtract 1/81 from 7/21, Solve 7/21

Subtract 1/81 from 7/21

7/21 - 1/81 is 26/81.

Find the least common denominator or LCM of the two denominators:
LCM of 21 and 81 is 567

Next, find the equivalent fraction of both fractional numbers with denominator 567
For the 1st fraction, since 21 × 27 = 567,
7/21 = 7 × 27/21 × 27 = 189/567
Likewise, for the 2nd fraction, since 81 × 7 = 567,
1/81 = 1 × 7/81 × 7 = 7/567
Subtract the two like fractions:
189/567 - 7/567 = 189 - 7/567 = 182/567
After reducing the fraction, the answer is 26/81

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