Answers

Add 21/70 and 3/42

21/70 + 3/42 is 13/35.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 70 and 42 is 210
   
   Next, find the equivalent fraction of both fractional numbers with denominator 210
2. For the 1st fraction, since 70 × 3 = 210,
   21/70 = 21 × 3/70 × 3 = 63/210
3. Likewise, for the 2nd fraction, since 42 × 5 = 210,
   3/42 = 3 × 5/42 × 5 = 15/210
4. Add the two like fractions:
   63/210 + 15/210 = 63 + 15/210 = 78/210
5. 78/210 simplified gives 13/35
6. So, 21/70 + 3/42 = 13/35

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