The slope of the graph, which shows the rate of change for Car A is 45. The unit rate is 45 miles per hour.
The slope is the rate of change, ratio, or unit rate between one value, quantity, or number and another.
The slope measures the steepness of a line.
We can compute the slope as the change in y (rise) divided by the change in x (run).
In this linear equation, y = 45x, the slope is 45. Therefore, we can conclude that the unit rate for Car A is 45 miles per hour.