Mohon bantuannya kak :)

Bab Fungsi Komposisi
Matematika SMA Kelas XI

(fog) (x) = 8x² + 2x + 11
f(2x + 1) = 8x² + 2x + 11
f(2 . x/2 + 1) = 8 . (x/2)² + 2 . (x/2) + 11
f(x + 1) = 2x² + x + 11
f(x -1 + 1) = 2(x - 1)² + (x - 1) + 11
f(x) = 2x² - 4x + 2 + x + 10
f(x) = 2x² - 3x + 12