Step-by-step explanation:
Given that the initial charge/fee for the first 5 minutes is $6
and also the additional rate per minutes is $0.6
we can model the total charges after the equation of a straight
that y= mx+c
now using the required notation
C= 0.6t+ 6
comparing this with the equation of a straight line
the constant term c is $6 flat rate for the first 5 minutes
the gradient 0.6 is m
the dependent variable x is t
and the cost C is y