How to plot inequalities in three dimesnions?

I have set of following inequalities {(x,y,z): x+2*y<=1, x-z<=2}

How to plot them in MATLAB? x,y and z are vectors.

Answer 1

[Azzi Abdelmalek]

Your inequalities have an infinity of solutions that you can't plot

[Abhinav]

I want to check the convexity of this set. Then how to do that?