Concept:
In Linear Programming Problems, the optimum value occurs at the corner points of the feasible region.
Step 1: {Find the feasible region vertices.}
The constraints are:
\[
x+y\le6,\quad x\ge0,\quad y\ge0
\]
Thus, the corner points are:
\[
(0,0),\ (6,0),\ (0,6)
\]
Step 2: {Evaluate the objective function.}
At \((0,0)\):
\[
Z=5(0)+3(0)=0
\]
At \((6,0)\):
\[
Z=5(6)+3(0)=30
\]
At \((0,6)\):
\[
Z=5(0)+3(6)=18
\]
Step 3: {Determine the maximum value.}
The maximum value is:
\[
30
\]
which occurs at:
\[
(6,0)
\]