Answers

Subtract 21/12 from 21/15

1^st number: 1 6/15, 2^nd number: 1 9/12

21/15 - 21/12 is -7/20.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 15 and 12 is 60
   
   Next, find the equivalent fraction of both fractional numbers with denominator 60
2. For the 1st fraction, since 15 × 4 = 60,
   21/15 = 21 × 4/15 × 4 = 84/60
3. Likewise, for the 2nd fraction, since 12 × 5 = 60,
   21/12 = 21 × 5/12 × 5 = 105/60
4. Subtract the two like fractions:
   84/60 - 105/60 = 84 - 105/60 = -21/60
5. After reducing the fraction, the answer is -7/20

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