Answers

Subtract 45/21 from 81/20

1^st number: 4 1/20, 2^nd number: 2 3/21

81/20 - 45/21 is 267/140.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 20 and 21 is 420
   
   Next, find the equivalent fraction of both fractional numbers with denominator 420
2. For the 1st fraction, since 20 × 21 = 420,
   81/20 = 81 × 21/20 × 21 = 1701/420
3. Likewise, for the 2nd fraction, since 21 × 20 = 420,
   45/21 = 45 × 20/21 × 20 = 900/420
4. Subtract the two like fractions:
   1701/420 - 900/420 = 1701 - 900/420 = 801/420
5. After reducing the fraction, the answer is 267/140
6. In mixed form: 1127/140

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