Answers

Subtract 20/90 from 4/81

4/81 - 20/90 is -14/81.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 81 and 90 is 810
   
   Next, find the equivalent fraction of both fractional numbers with denominator 810
2. For the 1st fraction, since 81 × 10 = 810,
   4/81 = 4 × 10/81 × 10 = 40/810
3. Likewise, for the 2nd fraction, since 90 × 9 = 810,
   20/90 = 20 × 9/90 × 9 = 180/810
4. Subtract the two like fractions:
   40/810 - 180/810 = 40 - 180/810 = -140/810
5. After reducing the fraction, the answer is -14/81

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