Answers

Add 21/72 and 42/20

1^st number: 21/72, 2^nd number: 2 2/20

21/72 + 42/20 is 287/120.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 72 and 20 is 360
   
   Next, find the equivalent fraction of both fractional numbers with denominator 360
2. For the 1st fraction, since 72 × 5 = 360,
   21/72 = 21 × 5/72 × 5 = 105/360
3. Likewise, for the 2nd fraction, since 20 × 18 = 360,
   42/20 = 42 × 18/20 × 18 = 756/360
4. Add the two like fractions:
   105/360 + 756/360 = 105 + 756/360 = 861/360
5. 861/360 simplified gives 287/120
6. So, 21/72 + 42/20 = 287/120
   In mixed form: 247/120

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