The base of the window will be 4 feet.
Explanation
Suppose, the base of the window is [tex]y[/tex] feet.
The window is in the shape of a rectangle and the height of the window is [tex](6x-7)[/tex] feet.
So, the area of the window will be: [tex]base*height = y(6x-7)[/tex] feet²
Given that, the area of the window is represented by the expression [tex](24x-28)[/tex] feet²
So, the equation will be ......
[tex]y(6x-7)= 24x-28\\ \\ y=\frac{24x-28}{6x-7}=\frac{4(6x-7)}{6x-7} =4[/tex]
Thus, the base of the window will be 4 feet.