A rectangular area is enclosed by a fence and divided by another section of fence parallel to two of its sides. If the 600m of fence used encloses a maximum area, what are the dimensions of the enclosure?

My work:

2L + 3W = 600

2L = 600 - 3W

L = 300 - 1.5W

A = LW

A = (300 - 1.5W)W

A = w(300 - 1.5W)

Zeros: X=0, X= 200

200/2 = 100

Width: 100

Length: 200

Correct ?