What’s the expression for “seven times x is no more than 15”

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.

Ineed with number 6 , explain how to get 1978

Піf x = y and y= z, which statement must be true? оа. -x = -2 b. x= z ос. —x = 2 od. 2= x