Left Hand Side,
$\frac{a^{p+q}}{a^{2r}}\times\frac{a^{q+r}}{a^{2p}}\times\frac{a^{r+p}}{a^{2q}}$
$=a^{p+q-2r}\times a^{q+r-2p}\times a^{r+p-2q}$
$=a^{\left(p+q-2r\right)+\left(^{q+r-2p}\right)+\left(r+p-2q\right)}$
$=a^{p+q-2r+^{q+r-2p}+r+p-2q}$
$=a^0$
$=1$
$=$ Right Hand Side [Proved]