im trying to find rhe optimal solution for a programming problem. not using excel or any technology.

the points i found for each contraint are: constraing $1(0,40)(50,0)$

constraint $2$ was $0\mathrm{.}2$y$<=5$ so i only found y$=25$

Constraint $3$: $(35,0(0,70)$

I already know the feasible region but dont know how to optimize fhe profit which is for the function z$=40$x$+30$y since i only have a y and not an x for constraint $2.$ solve it without technology!