If #x>=2, y-x>=-3, and x+y<=5#, what is the maximum value of #f(x,y)=x-4y#?
See details below
First, we have to draw the interception of three given conditions. We have something like this:
Where the intercpetions points are
By a famous theorem, we know that maximum values of a linear funtion lies in intersection points of restriction area. Thus we proof with this values
So, the maximum value occurs in