B is the midpoint of AC . find the following #6 and #7 please

How do you use the elimination method for this question? explain, because i really want to understand!

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.

Which shows the graph of the solution set of 3y – 2x > –18?