For all rational numbers

False.

Let $x=2, y=3$

Then.

LHS $=x-y$

$=2-3$

$=-1$

$\mathrm{RHS}=\mathrm{y}-\mathrm{x}$

$=3-2$

$=1$

By comparing LHS and RHS

$-1 \neq 1$

$\mathrm{LHS} \neq \mathrm{RHS}$