Answers

Subtract 8/90 from 21/20

1^st number: 1 1/20, 2^nd number: 8/90

21/20 - 8/90 is 173/180.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 20 and 90 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 90 × 2 = 180,
   8/90 = 8 × 2/90 × 2 = 16/180
4. Subtract the two like fractions:
   189/180 - 16/180 = 189 - 16/180 = 173/180

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