I: x-2y>=8
II:2x+y<=3
start by isolating y on a side
with I:
x-2y>=8
-2y>=8-x
2y<=x-8
y<=x/2-4
with II:
2x+y<=3
y<=-2x+3
now you can draw I' and II' and read of the solutions with the graph.
transform the inequalities into lines in slope intercept form by replacing the inequality with equality:
y<=x/2-4
->
y=x/2-4
y<=-2x+3
->
y=-2x+3
look at the inequalities to figure out if the area above or below is valid for each line (y<=... -> area below is valid->colored in the attached image)
the area in which all areas overlap is the solution space.