Answers

Subtract 25/20 from 21/90

1^st number: 21/90, 2^nd number: 1 5/20

21/90 - 25/20 is -61/60.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 90 and 20 is 180
   
   Next, find the equivalent fraction of both fractional numbers with denominator 180
2. For the 1st fraction, since 90 × 2 = 180,
   21/90 = 21 × 2/90 × 2 = 42/180
3. Likewise, for the 2nd fraction, since 20 × 9 = 180,
   25/20 = 25 × 9/20 × 9 = 225/180
4. Subtract the two like fractions:
   42/180 - 225/180 = 42 - 225/180 = -183/180
5. After reducing the fraction, the answer is -61/60

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