Answers

Add 42/84 and 18/90

42/84 + 18/90 is 7/10.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 84 and 90 is 1260
   
   Next, find the equivalent fraction of both fractional numbers with denominator 1260
2. For the 1st fraction, since 84 × 15 = 1260,
   42/84 = 42 × 15/84 × 15 = 630/1260
3. Likewise, for the 2nd fraction, since 90 × 14 = 1260,
   18/90 = 18 × 14/90 × 14 = 252/1260
4. Add the two like fractions:
   630/1260 + 252/1260 = 630 + 252/1260 = 882/1260
5. 882/1260 simplified gives 7/10
6. So, 42/84 + 18/90 = 7/10

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