Consider following optimization problem
Maximize$\ \ \ \ \ \ \ \ -x_1+x_2$
subjected to $\ \ \ \ \ \ \ 3x_1+4x_2=12$
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 2x_1-x_2\leq12$
$x_1,x_2\geq0$
It is given that start with initial basic feasible solution $(x_1,x_2)$=(4,0)
My question is now how to proceed further to solve the problem.