Answers

Subtract 20/42 from 20/54

20/54 - 20/42 is -20/189.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 54 and 42 is 378
   
   Next, find the equivalent fraction of both fractional numbers with denominator 378
2. For the 1st fraction, since 54 × 7 = 378,
   20/54 = 20 × 7/54 × 7 = 140/378
3. Likewise, for the 2nd fraction, since 42 × 9 = 378,
   20/42 = 20 × 9/42 × 9 = 180/378
4. Subtract the two like fractions:
   140/378 - 180/378 = 140 - 180/378 = -40/378
5. After reducing the fraction, the answer is -20/189

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