chatGPT is sometimes very funny. Q: substitute x=-1 in the LHS of the equation x^3 - 2x^2 - 4x = -8 and find the result. A: Sure, if we substitute x = -1 , we get: 1 = -8 The solution x=-1, x = 2 + sqrt(3)i, x = 2 - sqrt(3)i are correct.