Answers

Subtract 9/20 from 4/90

4/90 - 9/20 is -73/180.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 90 and 20 is 180
   
   Next, find the equivalent fraction of both fractional numbers with denominator 180
2. For the 1st fraction, since 90 × 2 = 180,
   4/90 = 4 × 2/90 × 2 = 8/180
3. Likewise, for the 2nd fraction, since 20 × 9 = 180,
   9/20 = 9 × 9/20 × 9 = 81/180
4. Subtract the two like fractions:
   8/180 - 81/180 = 8 - 81/180 = -73/180

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