Answers

Subtract 81/28 from 42/72

1^st number: 42/72, 2^nd number: 2 25/28

42/72 - 81/28 is -97/42.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 72 and 28 is 504
   
   Next, find the equivalent fraction of both fractional numbers with denominator 504
2. For the 1st fraction, since 72 × 7 = 504,
   42/72 = 42 × 7/72 × 7 = 294/504
3. Likewise, for the 2nd fraction, since 28 × 18 = 504,
   81/28 = 81 × 18/28 × 18 = 1458/504
4. Subtract the two like fractions:
   294/504 - 1458/504 = 294 - 1458/504 = -1164/504
5. After reducing the fraction, the answer is -97/42

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