Help me with this math problem please!

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.

You earn a 12% commission for every car you sell. how much is your commission if you sell a $23,000 car?

Roderick wants to draw a circle for which the numerical value of the circumference is greater than the value of the area.which lengths could he use for the radius? check all that apply