91影视

Let, $w$be the number of bottles of protein water and $b$be the number of protein bars that Mark buys.

Mark needs to eat at least an additional $80$grams of protein a day. The protein water supplies $27$grams of protein and the bar supplies $16$gram. So, the inequality is: $27w+16b鈮�80$.

A bottle of protein water costs $\$3.2$and a protein bar costs $\$1.75$. Mark has $\$10$dollars to spend, So, the inequality is: $3.2w+1.75b鈮�10$.

The system of inequalities is: localid="1653360697081" $\left\{\begin{array}{l}27w+16b鈮�80\\ 3.2w+1.75b鈮�10\end{array}\right.$

Below is the graph of the system of inequalities:$\left\{\begin{array}{l}27w+16b鈮�80\\ 3.2w+1.75b鈮�10\end{array}\right.$

As the point $(3,1)$is not in the double shaded region of the graph, so, Mark cannot buy $3$bottles of protein water and $1$ protein bar.

As the point $(0,5)$ is in the double shaded region of the graph, so, Mark can buy no bottles of protein water and $5$ protein bars.