The solid line indicates that the line itself is included in the solutions. That the shaded area is to the left, or under, the line means that y≤the line.
To find the equation of the line you first find the slope or m using any two points.
m=(y2-y1)/(x2-x1) in this case you are given (2,-5) and (-2, 3) so
m=(3--5)/(-2-2)
m=8/-4
m=-2
So far for y≤mx+b we have:
y=-2x+b using either point we can solve for b, I'll use (2,-5)
-5=-2(2)+b
-5=-4+b
-1=b
So the line is:
y=-2x-1 and since y≤ the line:
y≤-2x-1