First determine the closed-loop transfer function, using the feedback rule of block diagram simplification: KG (s) K3/3 K G₁(s) = = 1+ KG(s) 1+ K + 1+K ²½/_s³ +K The closed-loop poles are the roots of the denominator S³ +K = 0 which are calculated to be 3 S³ = -K S = -√K and s=³√K ±j√³³√K S Please show steps for simplification in red.