Section 15.2 Reference Topics

Here is a good site for graphing half-planes.
http://www.purplemath.com/modules/ineqgrph.htm

This is an interactive site which will graph half-planes. Write the given inequality in the form
Ax + By < C
or Ax + By > C
with the inputs on the other row zeros.
If you want to graph an inequality with equality included, then draw the boundary solid rather than the shown dashed boundary.
http://www.mhhe.com/math/devmath/aleks/wt-ia/student/olc/graphics/author_ed/chp3sec23.htm