Răspuns:
Explicație pas cu pas:
[tex]E(x)=\dfrac{4}{x-2} :\dfrac{(x+3)^{2}-(x+1)^{2}}{x^{2}-4}=\dfrac{4}{x-2} : \dfrac{(x+3+x+1)(x+3-x-1)}{(x-2)(x+2)}= \dfrac{4}{x-2} : \dfrac{(2x+4)*2}{(x-2)(x+2)}=\dfrac{4}{x-2} :\dfrac{2(x+2)*2}{(x-2)(x+2)}=\dfrac{4}{x-2} :\dfrac{4}{x-2} =1[/tex]
