The solution of the graph is on the area labeled D
How to find the solution of the graph
The solution of the graph can easily be found by plotting the graphs. The area where the shading coincides is the solution.
Also, from experience with inequalities, rewrite the equation x+3y ≤-3 to the form y = mx + b
x+3y ≤-3
= 3y ≤ -3 - x
= y ≤ - x/3 - 1
Having less than means the shading will be under the line
X ≥ 3: this means the shading will be to the right of the line
D is the point that match simultaneously: