Answers

Add 72/4 and 42/21

1^st number: 18 0/4, 2^nd number: 2 0/21

72/4 + 42/21 is 20/1.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 4 and 21 is 84
   
   Next, find the equivalent fraction of both fractional numbers with denominator 84
2. For the 1st fraction, since 4 × 21 = 84,
   72/4 = 72 × 21/4 × 21 = 1512/84
3. Likewise, for the 2nd fraction, since 21 × 4 = 84,
   42/21 = 42 × 4/21 × 4 = 168/84
4. Add the two like fractions:
   1512/84 + 168/84 = 1512 + 168/84 = 1680/84
5. 1680/84 simplified gives 20/1
6. So, 72/4 + 42/21 = 20/1

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