It's the slope-point formula:
[tex]y-y_1=m(x-x_1)[/tex]
We have:
[tex]y-5=-\dfrac{1}{2}(x+7)[/tex]
Therefore, the slope [tex]m=-\dfrac{1}{2}[/tex]
Point slope form
y -y1 = m(x - x1) where m = slope
In this case y - 5 = -1/2(x+7) , slope m = -1/2
Answer
Slope = -1/2