Answers

Add 84/28 and 20/21

1^st number: 3 0/28, 2^nd number: 20/21

84/28 + 20/21 is 83/21.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 28 and 21 is 84
   
   Next, find the equivalent fraction of both fractional numbers with denominator 84
2. For the 1st fraction, since 28 × 3 = 84,
   84/28 = 84 × 3/28 × 3 = 252/84
3. Likewise, for the 2nd fraction, since 21 × 4 = 84,
   20/21 = 20 × 4/21 × 4 = 80/84
4. Add the two like fractions:
   252/84 + 80/84 = 252 + 80/84 = 332/84
5. 332/84 simplified gives 83/21
6. So, 84/28 + 20/21 = 83/21
   In mixed form: 320/21

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