Use the substitution $x=e^{t}yp$ for $\frac{dy}{dt}$ and

$ypp$ for $\frac{d^{2}y}{d{t}^2}.x^2{y}^{\text{'}\text{'}}-17x{y}^{\text{'}}+81y=0$

Solve the original equation $by$ solving the new equation using the procedures $in$ Sections $4\mathrm{.}3-4\mathrm{.}5.$

$y(x)=,x>0$