Question

a garage chaged Mr Tilton $48 in parts and $36/h in labor many hours did the garage spend on Mr tilton's carr if total bill was$156

Answer 1

48 is a constant, so we take this out first
156 - 48 = 108

Since 36 is the variable, we can divide the above result to get the amount of hours.
108/36 = 3 hours

Answer 2

156 = 36x + 48

108 = 36x

3 = x

They spent 3 hours on the car.