Answers

Add 42/21 and 18/45

1^st number: 2 0/21, 2^nd number: 18/45

42/21 + 18/45 is 12/5.

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,
   42/21 = 42 × 15/21 × 15 = 630/315
3. Likewise, for the 2nd fraction, since 45 × 7 = 315,
   18/45 = 18 × 7/45 × 7 = 126/315
4. Add the two like fractions:
   630/315 + 126/315 = 630 + 126/315 = 756/315
5. 756/315 simplified gives 12/5
6. So, 42/21 + 18/45 = 12/5
   In mixed form: 22/5

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