Answers

Subtract 15/80 from 21/84

21/84 - 15/80 is 1/16.

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,
   21/84 = 21 × 20/84 × 20 = 420/1680
3. Likewise, for the 2nd fraction, since 80 × 21 = 1680,
   15/80 = 15 × 21/80 × 21 = 315/1680
4. Subtract the two like fractions:
   420/1680 - 315/1680 = 420 - 315/1680 = 105/1680
5. After reducing the fraction, the answer is 1/16

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