Respuesta :
Hello!
The answer is: a. [tex]\frac{3}{4}[/tex]
Why?
Since we are given the equation which represents the width of the border (x) we only need to isolate the variable (x), so:
[tex]2(8-2x)+2(4-2x)=18\\16-4x+8-4x=18\\24-8x=18\\8x=24-18\\8x=6\\x=\frac{6}{8}=\frac{3}{4}[/tex]
So, the width of the border is: [tex]\frac{3}{4}[/tex]
Have a nice day!