If α and β are the roots of the equation
$x^2 - 9x + 8 = 0$ (α > β) then find the value of
$α^2 - β^2$.

If the sum of the roots of the equation $x^2 + 8x + 2 - k = 0$ is twice the product of the roots.
Then find k.

Find the values of k ε R subject to the following condition :
The sum of the roots of $3x^2 + kx - 2 = 0$ is 6.

If the ratio of the roots of the equation $x^2 + 6x + k - 5 = 0$ is 3:5, then find the value of k.

If the roots of the equation $x^2 - 10x + k - 1 = 0$ are α and β and $α^3 + β^3 = 70$,
then find the value of k.