Answer:
The function to represent the area a of the section inside the border is [tex]A=12x-x^2[/tex]
Step-by-step explanation:
Given section inside the border is [tex]x[/tex] inches and [tex](12-x)[/tex] inches.
We need to write the function to represent the area of the section inside the border.
We can see the length of border is [tex]x[/tex] and width of the border is [tex](12-x)[/tex].
So, the area of the rectangle will be [tex]length\times width[/tex]
The area [tex](A)[/tex] will be
[tex]A=x(12-x)\\\\A=12x-x^2[/tex]
So, the function to represent the area a of the section inside the border is [tex]A=12x-x^2[/tex]