Answers

Add 70/18 and 54/21

1^st number: 3 16/18, 2^nd number: 2 12/21

70/18 + 54/21 is 407/63.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 18 and 21 is 126
   
   Next, find the equivalent fraction of both fractional numbers with denominator 126
2. For the 1st fraction, since 18 × 7 = 126,
   70/18 = 70 × 7/18 × 7 = 490/126
3. Likewise, for the 2nd fraction, since 21 × 6 = 126,
   54/21 = 54 × 6/21 × 6 = 324/126
4. Add the two like fractions:
   490/126 + 324/126 = 490 + 324/126 = 814/126
5. 814/126 simplified gives 407/63
6. So, 70/18 + 54/21 = 407/63
   In mixed form: 629/63

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