Answers

Subtract 72/21 from 8/4

1^st number: 2 0/4, 2^nd number: 3 9/21

8/4 - 72/21 is -10/7.

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,
   8/4 = 8 × 21/4 × 21 = 168/84
3. Likewise, for the 2nd fraction, since 21 × 4 = 84,
   72/21 = 72 × 4/21 × 4 = 288/84
4. Subtract the two like fractions:
   168/84 - 288/84 = 168 - 288/84 = -120/84
5. After reducing the fraction, the answer is -10/7

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