Answers

Add 18/21 and 98/90

1^st number: 18/21, 2^nd number: 1 8/90

18/21 + 98/90 is 613/315.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 21 and 90 is 630
   
   Next, find the equivalent fraction of both fractional numbers with denominator 630
2. For the 1st fraction, since 21 × 30 = 630,
   18/21 = 18 × 30/21 × 30 = 540/630
3. Likewise, for the 2nd fraction, since 90 × 7 = 630,
   98/90 = 98 × 7/90 × 7 = 686/630
4. Add the two like fractions:
   540/630 + 686/630 = 540 + 686/630 = 1226/630
5. 1226/630 simplified gives 613/315
6. So, 18/21 + 98/90 = 613/315
   In mixed form: 1298/315

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