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E(x)=(1/x-2. - x/x la puterea 2-4) : 2/(x-2)·(x+2). Aratati ca E(x)=1

Răspuns :

x la 2 -4= (x+2)(x-2)
amplificipe 1/x-2 cu x+2 si iti da= x+2/(x+2)(x-2)
 apoi vine (x+2-x/(x+2)(x-2)) ori (x+2)(x-2)/2  (la impartire cu fractii se inverseaza si semnul se schimba in inmultit)
2/(x+2)(x-2) ori (x+2)(x-2) (se taie(simplifica) (x+2) si (x-2) si ramana 2/2 =1
Salut,

[tex]E(x)=\left(\dfrac{1}{x-2}-\dfrac{x}{x^2-4}\right):\dfrac{2}{(x-2)(x+2)}=\\\\=\left[\dfrac{1}{x-2}-\dfrac{x}{(x-2)(x+2)}\right]:\dfrac{2}{x^2-4}=\dfrac{x+2-x}{(x-2)(x+2)}\cdot\dfrac{x^2-4}2=\\\\=\dfrac{2}{x^2-4}\cdot\dfrac{x^2-4}2=1.[/tex]

Green eyes.