Question 135335
Use synthetic division. At the end, you get k - 2k^2 and 3 ... These must sum to zero for x - k to be a factor.
3 + k - 2k^2 = 0
(3 - 2k)(1 + k) = 0
3 - 2k = 0 and 1 + k = 0
3/2 = k and k = -1

You would have to explain question (2) better.

x^3 = -27
x = -3 .. no complex values unless 0i - 3

Just multiply those out for (5)

I think Euler's equation might help for (ii) or the precalc version. It's been a long time since that.