(f°g)(x)=4x²+8x-3 , g(x)=2x+5 , f(x)=........?

(f o g)(x) = 4x^2 +8x - 3 dan g(x) = 2x + 5
f { g(x) } = 4x^2 + 8x - 3
f (2x + 5) = 4x^2 + 8x - 3
f (2x + 5) = (2x + 5)^2 -20x - 25 + 8x - 3
f (2x + 5) = (2x + 5)^2 -12x -28
f (2x + 5) = (2x +5)^2 - 6(2x +5) + 2
f (x) = x^2 - 6x +2

Menurut saya...............................