Two solutions to t${}^{}$y''+y'=0 are $y_1=ln(5t),y_2=ln(10).$

a$)$ Find the Wronskian.

$W=$

b$)$ If the solution satisfying the initial conditions $y(4)=0,y^{\text{'}}(4)=4$ is written as $y(t)=C_1{y}_1{C}_2{y}_2$ then what are the values of $C_1$ and $C_2$

$C_1=$

$C_2=$