x >= 0 & y >= 0 means the feasible region is in 1st quadrant.
Now, our equation is x + y <= 4
Let us take Origin (0, 0)
So, our equation becomes
0 + 0 <= 4
0 <= 4
Which is true,
Therefore, Origin (0, 0) lies in the feasible region. So, we shade the left side of the line.
Left side of line x + y <=4 and 1st axis makes the feasible region as marked in the graphic.
I suggest you look at the topics of Chpater 6 Class 11 Linear Inequality http://teachoo.com/4572/1617/-Example-9---Solve-3x---2y---6-graphically---Chapter-6/category/Graph---1-Equation/
Please check all questions in the list also.
Teachoo is free. Login to view more pages.
Login with facebook
Login with gmail
On signing up you are confirming that you have read and agree to
Terms of Service