Please help 12 points!!!!!

Answer:
100,100
Step-by-step explanation:
perimeter=400 m
length=x
let width=y
2(x+y)=400
x+y=200
y=200-x
area A=xy=x(200-x)=200x-x²
[tex]\frac{dA}{dx} =200-2x\\when \frac{dA}{dx} =0\\200-2x=0\\x=100\\\frac{d^2A}{dx^2} =-2<0~at~x=100\\so A ~is~maximum~length=100 ~m\\width=200-x=200-100=100 ~m[/tex]