We must translate the following sentence:
"The distance the plane traveled is the speed it was going times the number of hours it was flying".
to an equation.
In order to do that we define first the different variables in the equation:
d = distance
s = speed
h = numer of hours
Now, what is the meaning of speed? Speed is the distance traveled per unit of time (hour), so speed has units of distance over time, and h, the number of hours has units of time.
So in order to obtain a distance from the variables speed (s) and number of hours (h) we must multiply the speed by the number of hours:
[tex]d=s\cdot h[/tex]