Given:
The equation for the area of the first option is:
[tex]x^2+200x=166400[/tex]
Where x is the side length of the current square park.
To find:
The side length of the current square park.
Solution:
We have,
[tex]x^2+200x=166400[/tex]
It can be written as:
[tex]x^2+200x-166400=0[/tex]
Splitting the middle term, we get
[tex]x^2+520x-320x-166400=0[/tex]
[tex]x(x+520)-320(x+520)=0[/tex]
[tex](x-320)(x+520)=0[/tex]
[tex]x=320,-520[/tex]
We know that the side length of a park cannot be negative. So, the only possible value of x is 320.
Therefore, the most direct method to solve the given equation is splitting the middle term and the side length of the current square park is 320 meters.