gaokao 2015 Q2

gaokao · China · tianjin-science 5 marks Inequalities Linear Programming (Optimize Objective over Linear Constraints)
Variables $x, y$ satisfy the constraints $\left\{\begin{array}{c}x + 2 \geq 0, \\ x - y + 3 \geq 0, \\ 2x + y - 3 \leq 0,\end{array}\right.$ then the maximum value of the objective function $Z = x + 6y$ is
(A) 3
(B) 4
(C) 18
(D) 40
Variables $x, y$ satisfy the constraints $\left\{\begin{array}{c}x + 2 \geq 0, \\ x - y + 3 \geq 0, \\ 2x + y - 3 \leq 0,\end{array}\right.$ then the maximum value of the objective function $Z = x + 6y$ is

(A) 3

(B) 4

(C) 18

(D) 40