Question 238221
x is the length of one side of the rectangle
y is the width of one side of the rectangle

x*y = 7500

2x+2y = 400

x+y = 200

y = 200 - x (1)

Therefore

x*y = x(200-x) = 7500

200x-x^2 = 7500

Divide both sides by -1

x^2-200x = -7500

Complete the square

(x-100)^2 - 10000 = -7500

x = 2500^0.5 + 100

x = 150

y= 7500/150

so dimensions are 150 feet by 50 feet