Answer:
Givens
Notice that the window is a square, that means all four sides are congruent, so it has 8 meters in total, which would cost 24 euros plus the crystal. Therefore, the total cost of a window with 2 meters side is 24+12 = 36 euros.
Specifically, the function of the cost is: [tex]C(x)=3x+12[/tex], where [tex]x[/tex] represents meters of sides. (C)
[tex]60=3x+12\\60-12=3x\\x=\frac{48}{3}=16[/tex]
The window has 16 meters between the four sides, which gives 5 meters per side.
The graph of the function is attached.