Answers

Add 20/81 and 72/80

20/81 + 72/80 is 929/810.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 81 and 80 is 6480
   
   Next, find the equivalent fraction of both fractional numbers with denominator 6480
2. For the 1st fraction, since 81 × 80 = 6480,
   20/81 = 20 × 80/81 × 80 = 1600/6480
3. Likewise, for the 2nd fraction, since 80 × 81 = 6480,
   72/80 = 72 × 81/80 × 81 = 5832/6480
4. Add the two like fractions:
   1600/6480 + 5832/6480 = 1600 + 5832/6480 = 7432/6480
5. 7432/6480 simplified gives 929/810
6. So, 20/81 + 72/80 = 929/810
   In mixed form: 1119/810

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