Plz help! i am a dum dum lol

Find the given elements if matrix d:

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.

Find an equation of the line perpendicular to the graph of 28x-7y=9 that passes through the point at (4,1)