[tex]\it \dfrac{x-1}{2x-6}+ \dfrac{1}{3-x}= \dfrac{x-1}{2(x-3)}- \dfrac{^{2)}1}{\ x-3}= \dfrac{x-1-2}{2(x-3)}= \dfrac{x-3}{2(x-3)}=2,\ \forall\ x\ne3[/tex]
