Answers

Subtract 63/4 from 21/80

1^st number: 21/80, 2^nd number: 15 3/4

21/80 - 63/4 is -1239/80.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 80 and 4 is 80
   
   Next, find the equivalent fraction of both fractional numbers with denominator 80
2. For the 1st fraction, since 80 × 1 = 80,
   21/80 = 21 × 1/80 × 1 = 21/80
3. Likewise, for the 2nd fraction, since 4 × 20 = 80,
   63/4 = 63 × 20/4 × 20 = 1260/80
4. Subtract the two like fractions:
   21/80 - 1260/80 = 21 - 1260/80 = -1239/80

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