Answers

Subtract 27/12 from 18/21

1^st number: 18/21, 2^nd number: 2 3/12

18/21 - 27/12 is -39/28.

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,
   18/21 = 18 × 4/21 × 4 = 72/84
3. Likewise, for the 2nd fraction, since 12 × 7 = 84,
   27/12 = 27 × 7/12 × 7 = 189/84
4. Subtract the two like fractions:
   72/84 - 189/84 = 72 - 189/84 = -117/84
5. After reducing the fraction, the answer is -39/28

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