Answers

Add 81/21 and 42/45

1^st number: 3 18/21, 2^nd number: 42/45

81/21 + 42/45 is 503/105.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 21 and 45 is 315
   
   Next, find the equivalent fraction of both fractional numbers with denominator 315
2. For the 1st fraction, since 21 × 15 = 315,
   81/21 = 81 × 15/21 × 15 = 1215/315
3. Likewise, for the 2nd fraction, since 45 × 7 = 315,
   42/45 = 42 × 7/45 × 7 = 294/315
4. Add the two like fractions:
   1215/315 + 294/315 = 1215 + 294/315 = 1509/315
5. 1509/315 simplified gives 503/105
6. So, 81/21 + 42/45 = 503/105
   In mixed form: 483/105

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