Use f(x)=1/2x and f-^1(x)=2x to solve these problems

Which point on the x-axis lies on the line that passes through point c and is parallel to lino ab?

I'm confused on this could anyone me and show me what i need to do to solve it.

Tom is the deli manager at a grocery store. he needs to schedule employee to staff the deli department for no more that 260 person-hours per week. tom has one part-time employee who works 20 person-hours per week. each full-time employee works 40 person-hours per week. write and inequality to determine n, the number of full-time employees tom may schedule, so that his employees work on more than 260 person-hours per week. graph the solution set to this inequality.