Answer:
M=Main buses
C=Country buses
Step-by-step explanation:
so the charges from Main are $40 fee, then additional $2 for every mile you drive it for, so M = 40 + 2m
if your mileage is 20miles, when 2*20 is the charge
if your mileage is 50miles, when 2*50 is the charge
if your mileage is 1000miles, when 2*1000 is the charge
if your mileage is "m" miles, when 2*m is the charge
and County charges are $20 fee, then additional $3 for every mile... .so then C = 20 + 3m
if your mileage is 20miles, when 3*20 is the charge
if your mileage is 50miles, when 3*50 is the charge
if your mileage is 1000miles, when 3*1000 is the charge
if your mileage is "m" miles, when 3*m is the charge
so, their total charge is M and C respectively
when are the charges equal? well, when M = C
or
40 + 2m = 20 + 3m
solve for "m", to see at how many miles that happens
what will the charge be? plug that value for "m" on either, to get the charge