91影视

Let, $p$be the number of portraits and $l$be the number of landscapes that Caitlyn sells.

She wants to sell at least $60$drawings. So, the inequality is: $p+l鈮�60$.

She sells the portraits for $\$15$, the landscapes for $\$10$and she needs to sell at least $\$800$worth of drawings in order to earn a profit. So, the inequality is: $15p+10l鈮�800$.

Therefore, the system of inequalities is:$\left\{\begin{array}{l}p+l鈮�60\\ 15p+10l鈮�800\end{array}\right.$

Below is the graph of the system of inequalities: $\left\{\begin{array}{l}p+l鈮�60\\ 15p+10l鈮�800\end{array}\right.$

As the point $(20,35)$is not in the double shaded region of the graph, so, Caitlyn does not make a profit if she sells $20$ portraits and $35$ landscapes.

As the point $(50,20)$is in the double shaded region of the graph, so, Caitlyn makes a profit if she sells $50$ portraits and $20$ landscapes.