Ответ Автор - President01 (x^2+3x/x-1)' == [(x^2+3x)' * (x-1) - (x^2+3x) * (x-1)'] / ([-1)^2 == [2x+3(x-1) - x^2-3x] / (x-1)^2 == (2x+3x-3-x^2-3x) / (x^2-2x+1) == - (x^2-2x+3) / x^2-2x+1