Can you please help with this.​

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.

X+y=-4 x-y=2 use elimination with adding and subtraction

What is the slope of the line (-7,2) (4,6)