Answers

Subtract 20/81 from 21/8

1^st number: 2 5/8, 2^nd number: 20/81

21/8 - 20/81 is 1541/648.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 8 and 81 is 648
   
   Next, find the equivalent fraction of both fractional numbers with denominator 648
2. For the 1st fraction, since 8 × 81 = 648,
   21/8 = 21 × 81/8 × 81 = 1701/648
3. Likewise, for the 2nd fraction, since 81 × 8 = 648,
   20/81 = 20 × 8/81 × 8 = 160/648
4. Subtract the two like fractions:
   1701/648 - 160/648 = 1701 - 160/648 = 1541/648
5. In mixed form: 2245/648

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