$${ 5 }^{ 2y } =25THEN { 5 }^{ -y }$$
$E=\frac{125^{y}}{25HNT}$
$N\neq 0\text{ and }H\neq 0\text{ and }T\neq 0$
$H=\frac{125^{y}}{25ENT}$
$N\neq 0\text{ and }E\neq 0\text{ and }T\neq 0$