Answers

Subtract 81/28 from 84/90

1^st number: 84/90, 2^nd number: 2 25/28

84/90 - 81/28 is -823/420.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 90 and 28 is 1260
   
   Next, find the equivalent fraction of both fractional numbers with denominator 1260
2. For the 1st fraction, since 90 × 14 = 1260,
   84/90 = 84 × 14/90 × 14 = 1176/1260
3. Likewise, for the 2nd fraction, since 28 × 45 = 1260,
   81/28 = 81 × 45/28 × 45 = 3645/1260
4. Subtract the two like fractions:
   1176/1260 - 3645/1260 = 1176 - 3645/1260 = -2469/1260
5. After reducing the fraction, the answer is -823/420

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