It can be shown that $y_1=e^{2 x}$ and $y_2=xe^{2 x}$ are solutions to the differential equation $\frac{d^2y}{dx^2} - 4\frac{dy}{dx} + 4 y =0$.

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