Which table has no constant of proportionality y and x of 4

Jabari is power washing houses for a summer job. for every job, he charges an initial fee plus $30 for each hour of work. his total fee for a 4 -hour job, for instance, is $170 . jabari's total fee, f, for a single job is a function of the number, t, of hours it takes him to complete the job. write the function's formula.

Ineed to know the answer to this algebra question.

What is the inverse of the function f(x) = 2x + 1?