Answers

Subtract 90/16 from 28/20

1^st number: 1 8/20, 2^nd number: 5 10/16

28/20 - 90/16 is -169/40.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 20 and 16 is 80
   
   Next, find the equivalent fraction of both fractional numbers with denominator 80
2. For the 1st fraction, since 20 × 4 = 80,
   28/20 = 28 × 4/20 × 4 = 112/80
3. Likewise, for the 2nd fraction, since 16 × 5 = 80,
   90/16 = 90 × 5/16 × 5 = 450/80
4. Subtract the two like fractions:
   112/80 - 450/80 = 112 - 450/80 = -338/80
5. After reducing the fraction, the answer is -169/40

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