To calculate the slope, you can use the formula
[tex] \frac{{y}^{2} - {y}^{1}}{{x}^{2} - {x}^{1} } [/tex]
In this case,
[tex] \frac{( - 3) - ( - 3)}{8 - 5} [/tex]
Your slope is 0/3, which does not make sense so there should be something incorrect about your points.
