Solve the Linear Programming Problem $C = - 7 x + y$

Short Answer

Solve the linear programming problem.
Minimize
$C = - 7 x + y$
subject to $\begin{array} { l } x + 4 y \leq 12 \\4 x + 4 y \leq 20 \\x \geq 0 , y \geq 0\end{array}$ ​ $x =$ __________; $y =$ __________; $C =$ __________