Answer:
To calculate the slope, you can first substract the points to get the vector that join both, you may do it like this:
(-2, 11) - (5,6) = (-2 - 5, 11 - 6) = (-7, 5)
To get the slope when you get the vector (x,y), you will have to divide y be x:
5/-7
So the slope is 5/-7,