Respuesta :
f(h) = 40h + 120....when f(h) = 200
200 = 40h + 120
200 - 120 = 40h
80 = 40h
80/40 = h
2 = h <=== 2 hrs
200 = 40h + 120
200 - 120 = 40h
80 = 40h
80/40 = h
2 = h <=== 2 hrs
here is the answer my friend . Hope you give me a thank for the answer.