Answer:
+4
Explanation:
F(x,y) = 3x+y and y <= -2x+ 4 sub in for 'y'
= 3x + (-2x+4)
= x + 4
If you look at the graph for y <= - 2x+4 ( see below)
you will see that the domain (x values ) can only go from 0 to 4 and the max value is +4 ( rememeber too that y is restricted to >= 0 as is x )