Answers

Add 81/72 and 21/10

1^st number: 1 9/72, 2^nd number: 2 1/10

81/72 + 21/10 is 129/40.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 72 and 10 is 360
   
   Next, find the equivalent fraction of both fractional numbers with denominator 360
2. For the 1st fraction, since 72 × 5 = 360,
   81/72 = 81 × 5/72 × 5 = 405/360
3. Likewise, for the 2nd fraction, since 10 × 36 = 360,
   21/10 = 21 × 36/10 × 36 = 756/360
4. Add the two like fractions:
   405/360 + 756/360 = 405 + 756/360 = 1161/360
5. 1161/360 simplified gives 129/40
6. So, 81/72 + 21/10 = 129/40
   In mixed form: 39/40

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