Answer
Using speed formula:
[tex]\text{Speed} = \frac{\text{Distance}}{\text{Time}}[/tex]
Let y represents the distance in miles and x represents the time in hours.
As per the given statement:
Andrew drove 55 mph on his trip.
Using formula;
we have;
[tex]55 = \frac{y}{x}[/tex]
Multiply both sides by x we have;
[tex]y = 55x[/tex]
Therefore, the equation best represents the distance he drove is [tex]y = 55x[/tex]