find the domain of the composite function f o g fx6x9 gx63xS

find the domain of the composite function f o g.

f(x)=6/x-9; g(x)=63/x

f(x)=6/(x-9); g(x)=63/x

(f og)(x) = plug x= g(x) in f(x)

(fog)(x) = 6/( 63/x -9)

= 6x /( 63 -9x)

Now for Domain : At 63-9x =0 x = 7

So, at x=7 function does not exist

So, Domain: ( -inf, 7) U ( 7, inf)