Answers

Add 54/21 and 20/80

1^st number: 2 12/21, 2^nd number: 20/80

54/21 + 20/80 is 79/28.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 21 and 80 is 1680
   
   Next, find the equivalent fraction of both fractional numbers with denominator 1680
2. For the 1st fraction, since 21 × 80 = 1680,
   54/21 = 54 × 80/21 × 80 = 4320/1680
3. Likewise, for the 2nd fraction, since 80 × 21 = 1680,
   20/80 = 20 × 21/80 × 21 = 420/1680
4. Add the two like fractions:
   4320/1680 + 420/1680 = 4320 + 420/1680 = 4740/1680
5. 4740/1680 simplified gives 79/28
6. So, 54/21 + 20/80 = 79/28
   In mixed form: 223/28

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