Please DO NOT use Wronskian to solve.

please help me with solving this using variation of parameters. Please DO NOT use Wronskian to solve. My teacher said i have to use

y1v1'+y2v2'=0

y1'v1'+y2'v2'=f(t)/(a)

to find the solution the particular solution part of the equation.

This is the non homogeneous cauchy euler equation:

t^(2)y''+3ty'+y=t^(-1)