Răspuns :
(x²-49)/x(x-7)=(x-7)(x+7)/x(x-7)=(x+7)/x
2x+7)(x+1)= 2x²+7x+7+2x =2x²+9x+7
x(x+7)-(2x²+9x+7)=x²+7x-2x²-9x-7=-x²-2x-7
-(x²+2x+7)/x²
0
2x+7)(x+1)= 2x²+7x+7+2x =2x²+9x+7
x(x+7)-(2x²+9x+7)=x²+7x-2x²-9x-7=-x²-2x-7
-(x²+2x+7)/x²
0
[tex]E(x) =\dfrac{x^2-49}{x^2-7x} -\dfrac{2x+7}{x^2+x}:\dfrac{1}{x+1}
\\\;\\
= \dfrac{(x-7)(x+7)}{x(x-7)}-\dfrac{2x+7}{x(x+1)}\cdot\dfrac{x+1}{1} =\dfrac{x+7}{x}-\dfrac{2x+7}{x} =
\\\;\\
\dfrac{x+7-2x-7}{x}=\dfrac{-x}{x} = -1[/tex]