Jeśli x=[tex]\sqrt{2}[/tex] , oblicz sumę ułamków [tex]\frac{x}{x-1}[/tex]+[tex]\frac{x}{x+1}[/tex]

Odpowiedź :

[tex]\frac{x}{x-1}+\frac{x}{x+1}=\frac{x(x+1)}{(x-1)(x+1)}+\frac{x(x-1)}{(x-1)(x+1)}=\frac{2x^2}{x^2-1}\\\\\\\frac{2\cdot(\sqrt2)^2}{(\sqrt2)^2-1}=\frac{2\cdot2}{2-1}=\frac{4}{1}=4[/tex]