What is the value of x?

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.

What is the value of x in the this question ?

What are the first 4 terms in the multiplication pattern given by the formula 2×4n