Answer:
Step-by-step explanation:
Suppose the dimensions of the playground are x and y.
The total amount of the fence used is given and it is 780 ft. In terms of x and y this would be 3x+2y=780 (we add 3x because we want it to be cut in the middle). Therefore, y= 780/2-3/2x. Now, the total area (A )to be fenced is
A=x*y= x*(390-3/2x)=-3/2 x^2+390x
Calculating the derivative of A and setting it equals to 0 to find the maximum
A'= -3x+390=0
This yields x=130.
Therefore y=780/2-3/2*130=195
Thus, the maximum area is 130*195=25,350ft^2
