Solve This Problem Graphically $\mathrm { MAX } : \quad \mathbf { 8 \mathbf { X } _ { 1 } } + 4 \mathbf { X } _ { \mathbf { 2 } }$

Essay

Solve this problem graphically. What is the optimal solution and what constraints are binding at the optimal solution?
$\mathrm { MAX } : \quad \mathbf { 8 \mathbf { X } _ { 1 } } + 4 \mathbf { X } _ { \mathbf { 2 } }$
Subject to:
$$\begin{array} { l } 5 \mathbf { X } _ { 1 } + 5 \mathbf { X } _ { 2 } \leq 20 \\6 \mathbf { X } _ { 1 } + 2 \mathbf { X } _ { 2 } \leq 18 \\\mathbf { X } _ { 1 } , \mathbf { X } _ { \mathbf { 2 } } \geq 0\end{array}$$