If a car drives 65 miles in an hour, they would travel 65 miles in one hour. The equation for this would be 65x, with x representing the number of hours driven.
A good way to know how to solve a problem like this is to look at the units. Here we have miles per hour (65 miles/hour) and hours (5 hours) and we want to find X miles. So take a look at the units:
(Miles/hour) * (hours) = miles
So we can just plug in the values…
65 * 5 = 325
Whenever I get confused by a question like this I always try to remember that the word "per" just means divided by. So mph = miles/hour. And from there the algebra is pretty simple.
Another tip, your physics professor will always be tickled if at the end of your answer you list some of the assumptions you made like this: "assuming the car is traveling at a perfectly constant rate without stopping."
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