Question

Find a number k satisfying the given condition.
x + 2 is a factor of x^3 - kx^2 + 5x + 5k

Answer 1

well if x + 2 is a factor

then f(-2) = 0 this is the factor theorem

so substitute x = -2 and let the equation equal zero

then you should be able to solve for k

Answer 2

What about for x - 3 is a factor of x^4 - 3x^3 - kx^2 + 4x - 3? Does it change?

Answer 3

If (x - 3) is a factor then f(3) = 0