Answers

Subtract 81/80 from 18/84

1^st number: 18/84, 2^nd number: 1 1/80

18/84 - 81/80 is -447/560.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 84 and 80 is 1680
   
   Next, find the equivalent fraction of both fractional numbers with denominator 1680
2. For the 1st fraction, since 84 × 20 = 1680,
   18/84 = 18 × 20/84 × 20 = 360/1680
3. Likewise, for the 2nd fraction, since 80 × 21 = 1680,
   81/80 = 81 × 21/80 × 21 = 1701/1680
4. Subtract the two like fractions:
   360/1680 - 1701/1680 = 360 - 1701/1680 = -1341/1680
5. After reducing the fraction, the answer is -447/560

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