Conditie de existenta:
4x-12=0 => 4x=12 => x=3 => x apartine R\{3}(x diferit de 3)
[tex]\frac{-2}{2(2x-6)} \leq 0 = > \frac{-1}{2x-6}\leq 0 = > \frac{-1}{2(x-3)} \leq 0 = > \frac{-1}{x-3} \leq 0 = > \frac{1}{x-3}\geq 0 = > x-3 > 0 = > x > 3[/tex]
Cum x > 3 si x diferit de 3 (conditia de existenta) => x apartine (3;+inf)
