Ответы и объяснения

2013-05-11T16:43:13+04:00

((yx + y^2 + x^2 - yx)/x^2 - y^2) / ((x^2 + y^2)/x^2y^2) - (y^4/(x^2 -y^2) = ((y^2 + x^2)/(x^2 - y^2)) * (x^2y^2/(x^2 + y^2)) - (y^4/(x^2-y^2)) = (x^2y^2 - y^4)/ (x^2 - y^2) = (y^2(x^2 - y^2))/(x^2 - y^2)= y^2