F (x) = (3x -2) (4x+1)?

Jika x = 2 , maka :
F(2) = (3.2-2) . (4.2+1)
F(2) = (6-2) . (8+1)
F(2) = 4 . 9
F(2) = 36

ahh salah yaa:(

f(x)= (3x-2)(4x+1)
=12x2+3x-8x-2
=12x2-5x-2