91Ó°ÊÓ

Graph the systems of linear inequalities. In each case specify the vertices. Is the region convex? Is the region bounded? $$\left\\{\begin{aligned} -x+3 y & \leq 12 \\ x+y & \leq 8 \\ x & \geq 0 \\ y & \geq 0 \end{aligned}\right.$$

Solve for \(x\) and \(y\) in terms of \(a, b, c, d, e,\) and \(f\) $$\left\\{\begin{array}{l}a x+b y=c \\\dx+e y=f\end{array}\right.$$(Assume that \(a e-b d \neq 0\).)