Answer
Domain of\[f=\left\{ x|x\ne 4 \right\}\]
Work Step by Step
Division by 0 is undefined, so, exclude from the domain each function value of x for which the denominator is 0.
The denominator of $f\left( x \right)=\frac{5x}{x-4}$ is 0 if $x=4$.
Thus, x cannot be 4.
Domain of $f=\left\{ x|x\ne 4 \right\}$.
