Answers

Subtract 20/21 from 15/84

15/84 - 20/21 is -65/84.

Steps for subtracting fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 84 and 21 is 84
   
   Next, find the equivalent fraction of both fractional numbers with denominator 84
2. For the 1st fraction, since 84 × 1 = 84,
   15/84 = 15 × 1/84 × 1 = 15/84
3. Likewise, for the 2nd fraction, since 21 × 4 = 84,
   20/21 = 20 × 4/21 × 4 = 80/84
4. Subtract the two like fractions:
   15/84 - 80/84 = 15 - 80/84 = -65/84

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