Answers

Subtract 21/8 from 21/72

1^st number: 21/72, 2^nd number: 2 5/8

21/72 - 21/8 is -7/3.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 72 and 8 is 72
   
   Next, find the equivalent fraction of both fractional numbers with denominator 72
2. For the 1st fraction, since 72 × 1 = 72,
   21/72 = 21 × 1/72 × 1 = 21/72
3. Likewise, for the 2nd fraction, since 8 × 9 = 72,
   21/8 = 21 × 9/8 × 9 = 189/72
4. Subtract the two like fractions:
   21/72 - 189/72 = 21 - 189/72 = -168/72
5. After reducing the fraction, the answer is -7/3

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