A home gardener plans to enclose two rectangular gardens with fencing. The dimensions of the garden: x by 12-x, y by 12-x-y

a. Find the values of x and y that maximize the total area enclosed.
b. What is the maximum total area enclosed?
c. How many meters of fencing are needed?

3 answers

The total area A=A(x,y).
A=x(12-x)+y(12-x-y)=12x-x^2+12y-xy-y^2
Partial derivatives
A'x=12-2x-y
A'y=12-x-2y

Solve the equations A'x=A'y=0 => a. x=y=4
b. Amax=32+16=48
c. 24+16=40
hey thanks! but where did you get 16 in b?
y(12-x-y)=4(12-4-4)=16