Well to find the slope of anything you would use rise/run or [tex] \frac{y}{x} [/tex] right?
In this case its the exact same thing however there is a change between the two points and therefore you must find the difference.
So you would do [tex] \frac{ y_{2} -y_{1}}{x_{2}-x_{1}} [/tex] which would result in [tex] \frac{5}{7} [/tex]