Find the area of the largest rectangular garden that can be made so that one side of the

Question

house serves as the natural boundary and 10 m of fencing material is required for the
remaining three sides.

Answer 1

A = x y
x + 2y = 10
so
x = 10 -2 y
A = 10 y - 2 y^2
dA/dy = 10 - 4 y
= 0 for min or max
y = 10/4 = 5/2
x = 10 - 5 = 5
A = 25/2