How do we add and subtract rational expressions?

To find the common denominator, I need to find the least common multiple of x, x², and 2x. In this case the common denominator is 2x^2. So for the first one 2/x we mulitply 2x on the bottom and also on the top , so we are left with 4x/2x^2. Then 3/x^ you multiply 2 on the top and bottom , which becomes 6/2x^2. Last but not least the 1/2x you multiply x on the top and bottom which become , 1x/2x^2 , so =

4x   + 6  + 1x
      2x^2 

The denominator stays the same , but you add the like terms which =