In Problems $21-28,$ is the solution region bounded or unbounded?

$21.3x+y6$

$x0$

$y0$

$23.5x-2y10$

$x0$

$y0$

$25.-x+y4$

$x10$

$x0$

$y0$

$27.-x+2y2$

$2x-y2$

$x0$

$y0$

$22.$

$x+2y4$

$x0$

$y0$

$4x-3y12$

$x0$

$y0$

$x-y3$

$x9$

$x0$

$y0$

$-x+2y2$

$2x-y2$

$x0$

$y0$