Maximize: $\displaystyle 2x-3y$

Subject to:

$\displaystyle y-x \leq 5$

$\displaystyle x+y \leq 11$

$\displaystyle x \leq 4$

$\displaystyle x,y \geq 0$

I had to miss class and this is what we learned....if anyone knows of a good website with how-to or example problems that would be greatly helpful.

If not, a little help to start me off would be great and what I need to do.