A linear function $f(x,y)=ax+by+c$ has $no$ critical points. Therefore, the global minimum and maximum values $off(x,y)$

$on$ a closed and bounded domain must occur $on$ the boundary $of$ the domain. Furthermore, $it$ can $be$ easily seen that $if$ the

domain $is$ a polygon, then the global minimum and maximum values $off$ must occur $at$ a vertex $of$ the polygon.

Find the global minimum and maximum values $off(x,y)=4x-6y-2on$ the domain where $|x|+|y|5.$

$(Give$ your answers $as$ a whole numbers.$)$

global minimum: $|$

global maximur