Factoring by Short Multiplication: Solving the problem

Find the value of the parameter x.

$x^2-6x+8=0$

$x=2,x=4$

Find the value of the parameter x.

$9x^3-12x^2=0$

$x=0,x=\frac{4}{3}$

Find the value of the parameter x.

$-9x+3x^2=0$

$x=0,x=3$

Find the value of the parameter x.

$x^2+x=0$

$x=0,x=-1$