Answers

Subtract 90/21 from 9/4

1^st number: 2 1/4, 2^nd number: 4 6/21

9/4 - 90/21 is -57/28.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 4 and 21 is 84
   
   Next, find the equivalent fraction of both fractional numbers with denominator 84
2. For the 1st fraction, since 4 × 21 = 84,
   9/4 = 9 × 21/4 × 21 = 189/84
3. Likewise, for the 2nd fraction, since 21 × 4 = 84,
   90/21 = 90 × 4/21 × 4 = 360/84
4. Subtract the two like fractions:
   189/84 - 360/84 = 189 - 360/84 = -171/84
5. After reducing the fraction, the answer is -57/28

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