I'm not sure where to begin on this problem.

Find the absolute minimum and absolute maximum of

$\displaystyle f(x,y) = 7-5x+9y $ on the closed triangular region with vertices $\displaystyle (0,0), (9,0), (9,14) $. List the max/min values as well as the points at which they occur.

Min value:

Occurs at ( , )

Max value:

Occurs at ( , )

Thanks for the help!