Corners (read from graph): O(0,0), A(25,0), B (intersection of constraint lines), C(0,24).
Lines through given points: through A(25,0) and (0,400/9): 16x+9y=400.
Through C(0,24) and (48,0): x+2y=48.
Solving: x=16, y=16, so B=(16,16).
Z(0,0)=0, Z(25,0)=100, Z(16,16)=112, Z(0,24)=72. Maximum =112.
