Answers

Subtract 40/12 from 54/21

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

54/21 - 40/12 is -16/21.

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,
   54/21 = 54 × 4/21 × 4 = 216/84
3. Likewise, for the 2nd fraction, since 12 × 7 = 84,
   40/12 = 40 × 7/12 × 7 = 280/84
4. Subtract the two like fractions:
   216/84 - 280/84 = 216 - 280/84 = -64/84
5. After reducing the fraction, the answer is -16/21

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