Answers

Subtract 81/35 from 20/21

1^st number: 20/21, 2^nd number: 2 11/35

20/21 - 81/35 is -143/105.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 21 and 35 is 105
   
   Next, find the equivalent fraction of both fractional numbers with denominator 105
2. For the 1st fraction, since 21 × 5 = 105,
   20/21 = 20 × 5/21 × 5 = 100/105
3. Likewise, for the 2nd fraction, since 35 × 3 = 105,
   81/35 = 81 × 3/35 × 3 = 243/105
4. Subtract the two like fractions:
   100/105 - 243/105 = 100 - 243/105 = -143/105

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