Question

(x/x-y+2xy/x^2-2xy+y^2)*(2x/x+y-1) при x= -2; y= -1
/-дробь
^-степень
*-умножить

Answer 1

$.........=(frac{x}{x-y} + frac{2xy}{(x-y)(x-y)} )* (frac{2x}{x+y} -1)= frac{x(x-y)+2xy}{(x-y)(x-y)} * frac{2x-x-y}{x+y}= \ \ frac{ x^{2} -xy+2xy}{(x-y)(x-y)} * frac{x-y}{x+y} = frac{ x^{2} +xy}{(x-y)(x-y)} *frac{x-y}{x+y}= frac{x(x+y)}{(x-y)(x-y)}* frac{x-y}{x+y}= \ \ frac{x}{x-y}$

при  х= -2, у= -1

$frac{-2}{-2-(-1)}= frac{-2}{-2+1} = frac{-2}{-1} =2$