Aduceti la forma cea mai simpla expresia :
[tex]E(x) = \frac{2x+1}{x} + [ \frac{x}{x+1} - \frac{ x^{2} }{x-1} * ( \frac{1}{x} - \frac{1}{ x^{3} } )] : \frac{2x+1}{x+1} [/tex] , unde x ∈ R \ { -1 , - 1/2 , 0 , 1 }