Answers

Add 72/20 and 42/21

1^st number: 3 12/20, 2^nd number: 2 0/21

72/20 + 42/21 is 28/5.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 20 and 21 is 420
   
   Next, find the equivalent fraction of both fractional numbers with denominator 420
2. For the 1st fraction, since 20 × 21 = 420,
   72/20 = 72 × 21/20 × 21 = 1512/420
3. Likewise, for the 2nd fraction, since 21 × 20 = 420,
   42/21 = 42 × 20/21 × 20 = 840/420
4. Add the two like fractions:
   1512/420 + 840/420 = 1512 + 840/420 = 2352/420
5. 2352/420 simplified gives 28/5
6. So, 72/20 + 42/21 = 28/5
   In mixed form: 53/5

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