Answers

Add 21/42 and 21/54

21/42 + 21/54 is 8/9.

Steps for adding fractions

1. Find the least common denominator or LCM of the two denominators:
   LCM of 42 and 54 is 378
   
   Next, find the equivalent fraction of both fractional numbers with denominator 378
2. For the 1st fraction, since 42 × 9 = 378,
   21/42 = 21 × 9/42 × 9 = 189/378
3. Likewise, for the 2nd fraction, since 54 × 7 = 378,
   21/54 = 21 × 7/54 × 7 = 147/378
4. Add the two like fractions:
   189/378 + 147/378 = 189 + 147/378 = 336/378
5. 336/378 simplified gives 8/9
6. So, 21/42 + 21/54 = 8/9

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