Answers

Add 90/80 and 5/81

1^st number: 1 10/80, 2^nd number: 5/81

90/80 + 5/81 is 769/648.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 80 and 81 is 6480
   
   Next, find the equivalent fraction of both fractional numbers with denominator 6480
2. For the 1st fraction, since 80 × 81 = 6480,
   90/80 = 90 × 81/80 × 81 = 7290/6480
3. Likewise, for the 2nd fraction, since 81 × 80 = 6480,
   5/81 = 5 × 80/81 × 80 = 400/6480
4. Add the two like fractions:
   7290/6480 + 400/6480 = 7290 + 400/6480 = 7690/6480
5. 7690/6480 simplified gives 769/648
6. So, 90/80 + 5/81 = 769/648
   In mixed form: 1121/648

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