91影视

Let

$$\begin{gathered} x=numberofmicrowaves \\ y=numberofprinters \end{gathered}$$

The weight of microwaves and printers should not be greater than $160$pounds

$30x+20y鈮�160$

The volume of microwaves and printers should not be greater than$15cubicfeet$

$2x+3y鈮�15$

The number of microwaves always be greater or equal to zero

$x鈮�0$

The number of printers always be greater or equal to zero

$y鈮�0$

The system of inequalities is:

role="math" localid="1644489031556" $\left\{\begin{array}{l}30x+20y鈮�160\\ 2x+3y鈮�15\\ x鈮�0\\ y鈮�0\end{array}\right.$

The graph of the obtained system of inequalities is given as:

To determine if $4$microwaves and $2$printers can be carried on this trailer,

we look at the graph to see if the point$\left(4,2\right)$is in the solution region (dark blue).

Yes $\left(4,2\right)$is in the solution region so $4$ microwaves and $2$ printers can be carried on this trailer.

To determine if $7$microwaves and $3$printers can be carried on this trailer,

we look at the graph to see if the point $\left(7,3\right)$is in the solution region (dark blue).

No, it is not in the solution region.

So, $7$microwaves and$3$printers cannot be carried on the trailer.