Đáp án:
Giải thích các bước giải:
\(a)\dfrac{3x}{5x+5y}-\dfrac{x}{10x-10y}\\=\dfrac{3x}{5(x+y)}-\dfrac{x}{10(x-y)}\\=\dfrac{3x.2(x-y)-x(x+y)}{10(x-y)(x+y)}\\=\dfrac{6x^2 -6xy-x^2 -xy}{10(x-y)(x+y)}\\=\dfrac{5x^2 -7xy}{10(x-y)(x+y)}\\b.\dfrac{1}{3x-2}-\dfrac{4}{3x+2}-\dfrac{3x-6}{4-9x^2}\\=\dfrac{1}{3x-2}-\dfrac{4}{3x+2}+\dfrac{3x-6}{(3x-2)(3x+2)}\\=\dfrac{3x+2-4(3x-2)+3x-6}{(3x-2)(3x+2)}\\=\dfrac{3x+2-12x+8+3x-6}{(3x-2)(3x+2)}\\=\dfrac{-6x+4}{(3x-2)(3x+2)}\\=\dfrac{-2(3x-2)}{(3x-2)(3x+2)}\\=\dfrac{-2}{3x+2}\\c.\dfrac{6x-4}{x^2 -4}.\dfrac{x^2 -3x+2}{3x-2}\\\dfrac{2(3x-2)}{(x-2)(x+2)}.\dfrac{x^2 -x-2x+2}{3x-2}\\=\dfrac{2}{(x-2)(x+2)}.\dfrac{(x-1)(x-2)}{1}\\=\dfrac{2(x-1)}{x+2}\\=\dfrac{2x-2}{x+2}\)
