Answers

Subtract 64/18 from 21/20

1^st number: 1 1/20, 2^nd number: 3 10/18

21/20 - 64/18 is -451/180.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 20 and 18 is 180
   
   Next, find the equivalent fraction of both fractional numbers with denominator 180
2. For the 1st fraction, since 20 × 9 = 180,
   21/20 = 21 × 9/20 × 9 = 189/180
3. Likewise, for the 2nd fraction, since 18 × 10 = 180,
   64/18 = 64 × 10/18 × 10 = 640/180
4. Subtract the two like fractions:
   189/180 - 640/180 = 189 - 640/180 = -451/180

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