Christine is buying a picture package from Fabulous Photos. What is the rate of change?

A) $0.75 per picture
B) $2 per picture
C) $3 per picture
D) $4 per picture

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.