Answers

Add 28/84 and 42/21

1^st number: 28/84, 2^nd number: 2 0/21

28/84 + 42/21 is 7/3.

Steps for adding 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,
   28/84 = 28 × 1/84 × 1 = 28/84
3. Likewise, for the 2nd fraction, since 21 × 4 = 84,
   42/21 = 42 × 4/21 × 4 = 168/84
4. Add the two like fractions:
   28/84 + 168/84 = 28 + 168/84 = 196/84
5. 196/84 simplified gives 7/3
6. So, 28/84 + 42/21 = 7/3
   In mixed form: 21/3

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