Question

Thực hiện phép tính 

\(d,\dfrac{x-1}{3-x}\)\(+\dfrac{x^2+x}{x^2-9}\)

Answer 1

\(=\dfrac{-x^2-2x+3+x^2+x}{\left(x-3\right)\left(x+3\right)}=\dfrac{-x+3}{\left(x-3\right)\left(x+3\right)}=\dfrac{-1}{x+3}\)