Answers

Add 90/80 and 70/21

1^st number: 1 10/80, 2^nd number: 3 7/21

90/80 + 70/21 is 107/24.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 80 and 21 is 1680
   
   Next, find the equivalent fraction of both fractional numbers with denominator 1680
2. For the 1st fraction, since 80 × 21 = 1680,
   90/80 = 90 × 21/80 × 21 = 1890/1680
3. Likewise, for the 2nd fraction, since 21 × 80 = 1680,
   70/21 = 70 × 80/21 × 80 = 5600/1680
4. Add the two like fractions:
   1890/1680 + 5600/1680 = 1890 + 5600/1680 = 7490/1680
5. 7490/1680 simplified gives 107/24
6. So, 90/80 + 70/21 = 107/24
   In mixed form: 411/24

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