Question

The cost c of a car service is partly constant and partly varies with the time t is takes to do the work if it cost #35 for 95 1/2hrs service and #29 for 4 hr service find
(a) the formular connecting cost c and time t
(b) the cost of a 7 1/2 hrs srvices

Answer 1

cost = mt + b
given: when t=4, cost = 29
29 = 4m + b

given: when t = 95.5, cost = 35

this last part makes no sense, check your typing, then set up
the second equation just like I did the first.

then solve the 2 equations in 2 unknowns by subtracting them. That
eliminates the b and you can find m
etc,etc