Question

Se considera expresia E(x) = x²-49/x²-7x - 2x +7/x²+X : 1/x+1
Arătați că E(x)= -1

Answer 1

[tex]\displaystyle E(x)= \frac{(x-7)(x+7)}{x(x-7)} - \frac{2x+7}{x(x+1)} \cdot \frac{x+1}{1} \\ Ex(x)= \frac{x+7}{x} - \frac{2x+7}{x} \\ E(x)= \frac{x+7-2x-7}{x} = \frac{-x}{x} \\ E(x)=-1[/tex]