Answers

Add 12/8 and 84/21

1^st number: 1 4/8, 2^nd number: 4 0/21

12/8 + 84/21 is 11/2.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 8 and 21 is 168
   
   Next, find the equivalent fraction of both fractional numbers with denominator 168
2. For the 1st fraction, since 8 × 21 = 168,
   12/8 = 12 × 21/8 × 21 = 252/168
3. Likewise, for the 2nd fraction, since 21 × 8 = 168,
   84/21 = 84 × 8/21 × 8 = 672/168
4. Add the two like fractions:
   252/168 + 672/168 = 252 + 672/168 = 924/168
5. 924/168 simplified gives 11/2
6. So, 12/8 + 84/21 = 11/2
   In mixed form: 51/2

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