math equation

-3( k^3 - k) + 2k = 2k
-3( k^3 - k) = 0
k^3 - k = 0
k(k^2 - 1) = 0
k(k - 1)(k + 1) = 0
k = 0 or 1 or -1

-3( k^3 - k) = 0
-3k^3+3k=0
k(-3k^2+3)=0
k=0 or k=1

-3(k^3-k)+2k=2k
-3k^3+3k+2k=2k
-3k^3+5k=2k
-3k^3=2k-5k
-3k^3=-3k
k^3=-3k/-3
k^3=k
k=0
Ans:The solution is k=0.