Odpowiedź :
[tex]\\(\frac{x}{x-y}-\frac{2xy}{x^2-y^2}+\frac{x}{x+y}):\frac{2xy}{x+y}= \\\frac{x(x+y)-2xy+x(x-y)}{x^2-y^2}*\frac{x+y}{2x}= \\\frac{x^2+xy-2xy+x^2-xy}{(x+y)(x-y)}*\frac{x+y}{2x}= \\\frac{2x^2-2xy}{x-y}*\frac{1}{2x}=\frac{2x(x-y)}{x-y}*\frac{1}{2x}=1 \\c.n.d.[/tex]
x 2xy x 2x
(------- - ----------- + ---------) : (---------) =
x - y x² - y² x + y x + y
x(x + y) - 2xy + x(x - y) 2x(x - y)
------------------------------ : ----------------- =
(x + y)(x - y) (x + y)(x - y)
x² + xy - 2xy + x² - xy 2x² - 2xy
---------------------------- : ------------------ =
(x + y)(x - y) (x + y)(x - y)
2x² - 2xy (x + y)(x - y)
----------------- * -------------------- = 1
(x + y)(x - y) 2x² - 2xy
c.n.d.