Answers

Subtract 63/81 from 42/21

1^st number: 2 0/21, 2^nd number: 63/81

42/21 - 63/81 is 11/9.

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,
   42/21 = 42 × 27/21 × 27 = 1134/567
3. Likewise, for the 2nd fraction, since 81 × 7 = 567,
   63/81 = 63 × 7/81 × 7 = 441/567
4. Subtract the two like fractions:
   1134/567 - 441/567 = 1134 - 441/567 = 693/567
5. After reducing the fraction, the answer is 11/9
6. In mixed form: 12/9

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