Hello,
Dividing by 0 is not defined so let s take x different from 4 and -4 and then we can write:
As
[tex]f(x)=x^2-7x+12=x^2-4x-3x+12=x(x-4)-3(x-4)=(x-4)(x-3)\\ \\(f\times g)(x)=\dfrac{3(x-4)(x-3)}{(x-4)(x+4)}=\dfrac{3x-9}{x+4}[/tex]
Thanks
