Your drive your car for 4.5 hours at an avarage speed of miles per hour. how far did you go?

Well it depends, let’s say MPH is the variable M, you would take M and multiply it by the amount of hours. Thus an expression would look like this:

M x 4.5

If you were looking for an actual answer other than an expression, then please provide the miles per hour.

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Hope this helped, have a great day! :D