Answers

Add 4/21 and 15/84

4/21 + 15/84 is 31/84.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 21 and 84 is 84
   
   Next, find the equivalent fraction of both fractional numbers with denominator 84
2. For the 1st fraction, since 21 × 4 = 84,
   4/21 = 4 × 4/21 × 4 = 16/84
3. Likewise, for the 2nd fraction, since 84 × 1 = 84,
   15/84 = 15 × 1/84 × 1 = 15/84
4. Add the two like fractions:
   16/84 + 15/84 = 16 + 15/84 = 31/84
5. So, 4/21 + 15/84 = 31/84

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