Production Capacity Constraints:

Plant A: $0<=$ x$1+$ x$2<=400($Product X$),0<=$ x$3+$ x$4<=300($Product Y$)$

Plant B: $0<=$ x$5+$ x$6<=500($Product X$),0<=$ x$7+$ x$8<=400($Product Y$)$

Plant C: $0<=$ x$9+$ x$10<=600($Product X$),0<=$ x$11+$ x$12<=200($Product Y$)$

Demand Constraints:

Center $1$: x$1+$ x$5+$ x$9=200($Product X$),$ x$3+$ x$7+$ x$11=300($Product Y$)$

Center $2$: x$2+$ x$6+$ x$10=400($Product X$),$ x$4+$ x$8+$ x$12=100($Product Y$)$

Center $3$: x$3+$ x$7+$ x$11=300($Product X$),$ x$2+$ x$6+$ x$10=200($Product Y$)$

Center $4$: x$4+$ x$8+$ x$12=250($Product X$),$ x$1+$ x$5+$ x$9=150($Product Y$)$

How to create a graph to visualize and solve this linear programming problem: