Answers

Subtract 40/49 from 20/81

20/81 - 40/49 is -2260/3969.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 81 and 49 is 3969
   
   Next, find the equivalent fraction of both fractional numbers with denominator 3969
2. For the 1st fraction, since 81 × 49 = 3969,
   20/81 = 20 × 49/81 × 49 = 980/3969
3. Likewise, for the 2nd fraction, since 49 × 81 = 3969,
   40/49 = 40 × 81/49 × 81 = 3240/3969
4. Subtract the two like fractions:
   980/3969 - 3240/3969 = 980 - 3240/3969 = -2260/3969

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