Answers

Subtract 25/21 from 18/42

1^st number: 18/42, 2^nd number: 1 4/21

18/42 - 25/21 is -16/21.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 42 and 21 is 42
   
   Next, find the equivalent fraction of both fractional numbers with denominator 42
2. For the 1st fraction, since 42 × 1 = 42,
   18/42 = 18 × 1/42 × 1 = 18/42
3. Likewise, for the 2nd fraction, since 21 × 2 = 42,
   25/21 = 25 × 2/21 × 2 = 50/42
4. Subtract the two like fractions:
   18/42 - 50/42 = 18 - 50/42 = -32/42
5. After reducing the fraction, the answer is -16/21

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