Answers

Subtract 80/21 from 72/15

1^st number: 4 12/15, 2^nd number: 3 17/21

72/15 - 80/21 is 104/105.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 15 and 21 is 105
   
   Next, find the equivalent fraction of both fractional numbers with denominator 105
2. For the 1st fraction, since 15 × 7 = 105,
   72/15 = 72 × 7/15 × 7 = 504/105
3. Likewise, for the 2nd fraction, since 21 × 5 = 105,
   80/21 = 80 × 5/21 × 5 = 400/105
4. Subtract the two like fractions:
   504/105 - 400/105 = 504 - 400/105 = 104/105

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