Answers

Add 21/56 and 72/20

1^st number: 21/56, 2^nd number: 3 12/20

21/56 + 72/20 is 159/40.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 56 and 20 is 280
   
   Next, find the equivalent fraction of both fractional numbers with denominator 280
2. For the 1st fraction, since 56 × 5 = 280,
   21/56 = 21 × 5/56 × 5 = 105/280
3. Likewise, for the 2nd fraction, since 20 × 14 = 280,
   72/20 = 72 × 14/20 × 14 = 1008/280
4. Add the two like fractions:
   105/280 + 1008/280 = 105 + 1008/280 = 1113/280
5. 1113/280 simplified gives 159/40
6. So, 21/56 + 72/20 = 159/40
   In mixed form: 339/40

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