Answers

Subtract 21/81 from 2/90

2/90 - 21/81 is -32/135.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 90 and 81 is 810
   
   Next, find the equivalent fraction of both fractional numbers with denominator 810
2. For the 1st fraction, since 90 × 9 = 810,
   2/90 = 2 × 9/90 × 9 = 18/810
3. Likewise, for the 2nd fraction, since 81 × 10 = 810,
   21/81 = 21 × 10/81 × 10 = 210/810
4. Subtract the two like fractions:
   18/810 - 210/810 = 18 - 210/810 = -192/810
5. After reducing the fraction, the answer is -32/135

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