Answer
$f+g,f-g,fg,f/g$ : for all $x$ different from $0$
Work Step by Step
$f(x)+g(x)=6-1/x+1/x=6$
for all $x\ne0$
$f(x)-g(x)=6-1/x-1/x=6-2/x$
for all $x\ne0$
$f(x)\times g(x)=(6-1/x)\times1/x=6/x-1/x^2$
for all $x\ne0$
$f(x)/g(x)=(6-1/x)/(1/x)=6x-1$
for all $x\ne0$
