I need help on 7 a-c. it could really help me if someone helps.

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 always true when two whole numbers are subtracted?

12 3 4 5 6 7 8 9 10time remaining01: 24: 54which graph represents this system? y=1/2x + 3 y= 3/2x -1