Subtract 3/81 from 5/21, Solve 5/21

Subtract 3/81 from 5/21

5/21 - 3/81 is 38/189.

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,
5/21 = 5 × 27/21 × 27 = 135/567
Likewise, for the 2nd fraction, since 81 × 7 = 567,
3/81 = 3 × 7/81 × 7 = 21/567
Subtract the two like fractions:
135/567 - 21/567 = 135 - 21/567 = 114/567
After reducing the fraction, the answer is 38/189

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