<PRE><B>Question 46989</B>
c^3-3c^2-9c+27=0
(c^3-3c^2)+(-9c+27)=0
c^2(c-3)+(-9)(c-3)=0
(c^2-9)(c-3)=0
(c-3)(c+3)(c-3)=0
(c+3)(c-3)^2=0
So,c+3=0 or c-3=0
c=-3 or3



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