Question 169676
so if melanie can paint the barn in x days and Melissa can do it in 2x days then the portion melanie does per day is (1/x) and the portion Melissa does per day is (1/2x)

together they can paint the barn in (t/x)+(t/2x)=1job.....that is the rational expression for the fraction of the barn they can complete in 1day.

if x=5days then 2x=10days...together they can paint the barn in
:
(t/5)+(t/10)=1----> multiply terms by 10--->2t+1t=10--->3t=10
:

{{{highlight(t=10/3)}}}days for both to paint the barn if x=5