A car is traveling at a speed of 55 miles per hour. you want to write an algebraic expression to show how far the car will travel in a certain number of hours. What will be your constant your variable

Speed=Distance/Time

So Distance=Speed X Time

Distance=55T

Where 55 is the Car's speed and it is constant (won't change) and T is the time which is the changing variable.

you can plug time values to know the distance traveled!