Given $x^2-5x=0$, which method is most efficient in solving it, and why?

Quadratic formula, because factoring is not practical when $c=0$

Square-root property, since the expression is already a perfect square

Factoring, because $c=0$, so $x$ can be factored out immediately to yield $x(x-5)=0$

Completing the square, because $a=1$ and $b$ is odd