[tex]\mathbf{Task.} ~ f(x)=\sqrt{x+8}; ~ g(x)=8x-12. ~ \mathrm{Find} ~ f(g(x)).[/tex]
[tex]f(g(x))=\sqrt{g(x)+8}=\sqrt{8x-12 + 8}=\sqrt{8x-4}=[/tex]
[tex]=\sqrt{4(2x-1)}=2\sqrt{2x-1}.[/tex]
[tex]Answer \colon f(g(x))=2\sqrt{2x-1}. ~ \blacktriangle[/tex]
