You can
put this solution on YOUR website!the area of the rectangle is the product of the x and y coordinates on the y=8-2x line...this means A(x)=x(8-2x)...or
the graph of A(x) is a downward opening parabola with zeros at x=0 and x=4...the axis of symmetry (and the maximum point) is midway between the zeros at x=2
so for x=2...A(x)=8...and y=4