Answers

Subtract 18/12 from 15/21

1^st number: 15/21, 2^nd number: 1 6/12

15/21 - 18/12 is -11/14.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 21 and 12 is 84
   
   Next, find the equivalent fraction of both fractional numbers with denominator 84
2. For the 1st fraction, since 21 × 4 = 84,
   15/21 = 15 × 4/21 × 4 = 60/84
3. Likewise, for the 2nd fraction, since 12 × 7 = 84,
   18/12 = 18 × 7/12 × 7 = 126/84
4. Subtract the two like fractions:
   60/84 - 126/84 = 60 - 126/84 = -66/84
5. After reducing the fraction, the answer is -11/14

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