Answer: [tex]A(x)=14x+40[/tex]
Step-by-step explanation:
Given : The dimension of a rectangle is (x+10)ft. by (x+4)ft.
Then, Area of rectangle will be :-
[tex]A_1(x)=(x+10)\times(x+4)=x^2+(10+4)x+40\\\\\Rightarrow\ A_1(x)=x^2+14x+40[/tex]
If a square of length xft on a side is cut from the rectangle, then the area of the square :-
[tex]A_2(x)=x^2[/tex]
Now, the remaining area in the form of a polynomial function A(x) will be :-
[tex]A(x)=A_1(x)-A_2(x)\\\\=x^2+14x+40-x^2=14x+40[/tex]
Hence, the remaining area in the form of a polynomial function A(x) will be :-
[tex]A(x)=14x+40[/tex]