Equation with x to the denominator:
The value of x must not reduce to zero the denominator !

Go !

$\frac{3x-6}{x-3}= 2-\frac{3}{3-x}$ $x = 3 \qquad : \qquad S=\{ \}$
$\frac{x}{x+2}-\frac{1}{x-2}=\frac{2}{x+2}-\frac{x+2}{x^2-4}$