Answers

Subtract 84/72 from 20/42

1^st number: 20/42, 2^nd number: 1 12/72

20/42 - 84/72 is -29/42.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 42 and 72 is 504
   
   Next, find the equivalent fraction of both fractional numbers with denominator 504
2. For the 1st fraction, since 42 × 12 = 504,
   20/42 = 20 × 12/42 × 12 = 240/504
3. Likewise, for the 2nd fraction, since 72 × 7 = 504,
   84/72 = 84 × 7/72 × 7 = 588/504
4. Subtract the two like fractions:
   240/504 - 588/504 = 240 - 588/504 = -348/504
5. After reducing the fraction, the answer is -29/42

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