Answers

Add 90/21 and 28/40

1^st number: 4 6/21, 2^nd number: 28/40

90/21 + 28/40 is 349/70.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 21 and 40 is 840
   
   Next, find the equivalent fraction of both fractional numbers with denominator 840
2. For the 1st fraction, since 21 × 40 = 840,
   90/21 = 90 × 40/21 × 40 = 3600/840
3. Likewise, for the 2nd fraction, since 40 × 21 = 840,
   28/40 = 28 × 21/40 × 21 = 588/840
4. Add the two like fractions:
   3600/840 + 588/840 = 3600 + 588/840 = 4188/840
5. 4188/840 simplified gives 349/70
6. So, 90/21 + 28/40 = 349/70
   In mixed form: 469/70

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