It can be shown that $y_1=e^{2 x}$ and $y_2=e^{-8 x}$ are solutions to the differential equation $D^2 y + 6 Dy - 16 y =0$.

$W(y_1,y_2)$ = .
$c_1y_1+c_2y_2$ is the general solution to the equation on the interval