Given that,
The area of the rectangle, [tex]A=x^2-114[/tex]
Length of the rectangle, [tex]l=x+12\ m[/tex]
To find,
The width of the rectangle.
Solution,
The formula for the area of a rectangle is given by :
A = lb
b is width of the rectangle
[tex]b=\dfrac{A}{l}\\\\b=\dfrac{x^2-114}{x+12}\\\\b=\dfrac{x^2-12^2}{x+12}\\\\b=\dfrac{(x-12)(x+12)}{(x+12)}\\\\=(x-12)\ m[/tex]
So, the width of the rectangle is (x-12) m.