The solution y =? Of the differential equation y '' + 2Y '+ y = 0?

The solution y =? Of the differential equation y '' + 2Y '+ y = 0?

This is a second order homogeneous linear differential equation with constant coefficients
Characteristic equation R ^ 2 + 2R + 1 = 0
(r+1)^2=0
r1=r2=-1
y=(C1+C2x)e^(r1x)=(C1+C2x)e^-x