Rút gọn biểu thức:A=2x/x-3 -1/x+3 + 2x²-12/9-x² và B=2x-2/5. Hứa trả 5sao

A=$\dfrac{2x}{x-3}$ -$\dfrac{1}{x+3}$+ $\dfrac{2x²-12}{9-x²}$

=$\dfrac{2x}{x-3}$ -$\dfrac{1}{x+3}$- $\dfrac{2x²-12}{x²-9}$

=$\dfrac{2x}{x-3}$ -$\dfrac{1}{x+3}$- $\dfrac{2x²-12}{(x-3)(x+3)}$

=$\dfrac{2x^2+6x}{(x-3)(x+3)}$ -$\dfrac{(x-3)}{(x+3)(x-3)}$- $\dfrac{2x²-12}{(x-3)(x+3)}$

=$\dfrac{2x^2+6x-x+3-2x^2+12}{(x-3)(x+3)}$

=$\dfrac{5x+15}{(x-3)(x+3)}$

=$\dfrac{5(x+3)}{(x-3)(x+3)}$

=$\dfrac{5}{(x-3}$ 

B=2x-$\dfrac{2}{5}$

=$\dfrac{2x.5}{5}$-$\dfrac{2}{5}$

=$\dfrac{10x}{5}$-$\dfrac{2}{5}$

=$\dfrac{10x-2}{5}$