given that Colton gym charges initial fee of $40
there is an addiontional fee of $50
C is the cost of joining the gym
m is the number of months
so the equation that can show the cost of joining the gym in m month is:
$40 which is the initial feel been added to $50 the additional charge multiply by m the number of months.
therefore the equation is:
C = 40 + 50m
so the correct option is B