Question

A car is traveling at a speed of 55 mph. 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? What is your variable?

Answer 1

distance = rate * time.

distance is number of miles the car has traveled.

rate = number of miles per hour the car is traveling at.

time = number of hours the car has been driven.

let D = distance.

let T = time.

let R = rate

the general equation is D = R*T

as long as the car will always be driven at 55 miles per hour, you can substitute 55 for R and that becomes your constant.

The equation then becomes D = 55 * T.

example:

you drive 5 hours.

D = 55 * T = 55 * 5 = 275 miles.

If you drive at 55 miles per hour for 5 hours, you will have driven 275 miles.

Hope this helps!