Answers

Subtract 56/81 from 42/84

42/84 - 56/81 is -31/162.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 84 and 81 is 2268
   
   Next, find the equivalent fraction of both fractional numbers with denominator 2268
2. For the 1st fraction, since 84 × 27 = 2268,
   42/84 = 42 × 27/84 × 27 = 1134/2268
3. Likewise, for the 2nd fraction, since 81 × 28 = 2268,
   56/81 = 56 × 28/81 × 28 = 1568/2268
4. Subtract the two like fractions:
   1134/2268 - 1568/2268 = 1134 - 1568/2268 = -434/2268
5. After reducing the fraction, the answer is -31/162

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