Answers

Subtract 70/81 from 20/30

20/30 - 70/81 is -16/81.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 30 and 81 is 810
   
   Next, find the equivalent fraction of both fractional numbers with denominator 810
2. For the 1st fraction, since 30 × 27 = 810,
   20/30 = 20 × 27/30 × 27 = 540/810
3. Likewise, for the 2nd fraction, since 81 × 10 = 810,
   70/81 = 70 × 10/81 × 10 = 700/810
4. Subtract the two like fractions:
   540/810 - 700/810 = 540 - 700/810 = -160/810
5. After reducing the fraction, the answer is -16/81

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