Answers

Subtract 3/4 from 20/81

20/81 - 3/4 is -163/324.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 81 and 4 is 324
   
   Next, find the equivalent fraction of both fractional numbers with denominator 324
2. For the 1st fraction, since 81 × 4 = 324,
   20/81 = 20 × 4/81 × 4 = 80/324
3. Likewise, for the 2nd fraction, since 4 × 81 = 324,
   3/4 = 3 × 81/4 × 81 = 243/324
4. Subtract the two like fractions:
   80/324 - 243/324 = 80 - 243/324 = -163/324

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