Answers

Add 81/21 and 70/8

1^st number: 3 18/21, 2^nd number: 8 6/8

81/21 + 70/8 is 353/28.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 21 and 8 is 168
   
   Next, find the equivalent fraction of both fractional numbers with denominator 168
2. For the 1st fraction, since 21 × 8 = 168,
   81/21 = 81 × 8/21 × 8 = 648/168
3. Likewise, for the 2nd fraction, since 8 × 21 = 168,
   70/8 = 70 × 21/8 × 21 = 1470/168
4. Add the two like fractions:
   648/168 + 1470/168 = 648 + 1470/168 = 2118/168
5. 2118/168 simplified gives 353/28
6. So, 81/21 + 70/8 = 353/28
   In mixed form: 1217/28

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