Solve the following IVP showing details of your work:

a$.x^2{y}^{\text{'}\text{'}}+3x{y}^{\text{'}}+y=0,y(1)=3\mathrm{.}6,y^{\text{'}}(1)=0\mathrm{.}4$

b$.5x^2{y}^{\text{'}\text{'}}+23x{y}^{\text{'}}+16\mathrm{.}2y=0$

c$.x^2{y}^{\text{'}\text{'}}-2x{y}^{\text{'}}-4y=0$