There exists a polynomial $(x) and a constant 7k such that (x^2 - 2x - 5) f(x) = x^4 - 2x^3 + kx^2 What is k?
Note that if f(x) = x^2 we have
(x^2 - 2x - 5) * x^2 = x^4 - 2x^3 - 5x^2
So
k = -5