Problems: Solve the following differential equations, using the initial conditions when applicable

$y_1^{\text{'}\text{'}}+8y_1^{\text{'}}+16y_1=0,y_1(0)=1,y_1^{\text{'}}(0)=0$

$y_2^{\text{'}\text{'}}-3y_2^{\text{'}}+2y_2=0,y_2(1)=1,y_2^{\text{'}}(1)=4$

$y_3^{\text{'}\text{'}}+8y_3^{\text{'}}+17y_3=0$

$y_4^{IV}+8y_4^{II}+16y_4=0$

$y_5^{VI}-729y_5=0$