Answers

Subtract 21/81 from 2/42

2/42 - 21/81 is -40/189.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 42 and 81 is 1134
   
   Next, find the equivalent fraction of both fractional numbers with denominator 1134
2. For the 1st fraction, since 42 × 27 = 1134,
   2/42 = 2 × 27/42 × 27 = 54/1134
3. Likewise, for the 2nd fraction, since 81 × 14 = 1134,
   21/81 = 21 × 14/81 × 14 = 294/1134
4. Subtract the two like fractions:
   54/1134 - 294/1134 = 54 - 294/1134 = -240/1134
5. After reducing the fraction, the answer is -40/189

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