Answers

Subtract 81/80 from 5/42

1^st number: 5/42, 2^nd number: 1 1/80

5/42 - 81/80 is -1501/1680.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 42 and 80 is 1680
   
   Next, find the equivalent fraction of both fractional numbers with denominator 1680
2. For the 1st fraction, since 42 × 40 = 1680,
   5/42 = 5 × 40/42 × 40 = 200/1680
3. Likewise, for the 2nd fraction, since 80 × 21 = 1680,
   81/80 = 81 × 21/80 × 21 = 1701/1680
4. Subtract the two like fractions:
   200/1680 - 1701/1680 = 200 - 1701/1680 = -1501/1680

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