Answers

Add 21/8 and 42/81

1^st number: 2 5/8, 2^nd number: 42/81

21/8 + 42/81 is 679/216.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 8 and 81 is 648
   
   Next, find the equivalent fraction of both fractional numbers with denominator 648
2. For the 1st fraction, since 8 × 81 = 648,
   21/8 = 21 × 81/8 × 81 = 1701/648
3. Likewise, for the 2nd fraction, since 81 × 8 = 648,
   42/81 = 42 × 8/81 × 8 = 336/648
4. Add the two like fractions:
   1701/648 + 336/648 = 1701 + 336/648 = 2037/648
5. 2037/648 simplified gives 679/216
6. So, 21/8 + 42/81 = 679/216
   In mixed form: 331/216

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