The general solution of the differential equation y "+ 8y '+ 16y = 0 is?

The general solution of the differential equation y "+ 8y '+ 16y = 0 is?

Characteristic equation: R & # 178; + 8R + 16 = 0
(r+4)²=0
r1=r2=-4
So the general equation y = (C1 + c2x) e ^ (- 4x)