Barn Painting. Melanie can paint a certain barn by herself in x days. Her helper Melissa can paint the same barn by herself in 2x days. Write a rational expression for the fractions of the barn that they complete in one day by working together. Evaluate the expression for x = 5.

I came up with this:

Melanie = 1/x

Melissa = 1/2x

Together = 1/x

1/x + 1/2x = 1/x

What is the right set up?

I can evaluate when x= 5. I just need the proper rational expression.

Thanks