Answers

Add 90/21 and 98/20

1^st number: 4 6/21, 2^nd number: 4 18/20

90/21 + 98/20 is 643/70.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 21 and 20 is 420
   
   Next, find the equivalent fraction of both fractional numbers with denominator 420
2. For the 1st fraction, since 21 × 20 = 420,
   90/21 = 90 × 20/21 × 20 = 1800/420
3. Likewise, for the 2nd fraction, since 20 × 21 = 420,
   98/20 = 98 × 21/20 × 21 = 2058/420
4. Add the two like fractions:
   1800/420 + 2058/420 = 1800 + 2058/420 = 3858/420
5. 3858/420 simplified gives 643/70
6. So, 90/21 + 98/20 = 643/70
   In mixed form: 913/70

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