solve that

Given, $\frac{x}{5}=\frac{x-1}{6}$

$\Rightarrow$ $6 x=5(x-1)$ [by cross-multiplication]

$\Rightarrow$ $6 x=5 x-5$

$\Rightarrow$ $6 x-5 x=-5$ [transposing $5 x$ to LHS]

$\therefore$ $x=-5$