Answers

Add 84/81 and 21/40

1^st number: 1 3/81, 2^nd number: 21/40

84/81 + 21/40 is 1687/1080.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 81 and 40 is 3240
   
   Next, find the equivalent fraction of both fractional numbers with denominator 3240
2. For the 1st fraction, since 81 × 40 = 3240,
   84/81 = 84 × 40/81 × 40 = 3360/3240
3. Likewise, for the 2nd fraction, since 40 × 81 = 3240,
   21/40 = 21 × 81/40 × 81 = 1701/3240
4. Add the two like fractions:
   3360/3240 + 1701/3240 = 3360 + 1701/3240 = 5061/3240
5. 5061/3240 simplified gives 1687/1080
6. So, 84/81 + 21/40 = 1687/1080
   In mixed form: 1607/1080

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