Answer :
F(k): f=x+24/2kx
F(a/2): a=x+24/fx
F(x-1): f=x+24/2x^2-2x
F(2x+3):f=x+24/4x^2+6x
F(x+h): f=x+24/2hx+2x^2
F(a/2): a=x+24/fx
F(x-1): f=x+24/2x^2-2x
F(2x+3):f=x+24/4x^2+6x
F(x+h): f=x+24/2hx+2x^2