a rectangular field of fixed area is to be enclosed. It is divided into five lots by parallels to one of the sides. A total of 10,000 meters of fence are available. Find the area of the largest field that can be enclosed.

help me pleaseeeeeeeeeeeee

as always, split the fence between lengths and widths for maximum area.

If the dimensions are x and y, then
2x+6y = 10000
so the length is 5000/2
and the width is 5000/6
you can go the calculus route by setting
A = xy = x(10000-2x)/6
dA/dx = 0 at x = 2500