Answers

Subtract 10/81 from 20/21

20/21 - 10/81 is 470/567.

Steps for subtracting fractions

1. 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
2. For the 1st fraction, since 21 × 27 = 567,
   20/21 = 20 × 27/21 × 27 = 540/567
3. Likewise, for the 2nd fraction, since 81 × 7 = 567,
   10/81 = 10 × 7/81 × 7 = 70/567
4. Subtract the two like fractions:
   540/567 - 70/567 = 540 - 70/567 = 470/567

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