Question

[Zi Heo]

Thực hiện phép tính

a, \(\dfrac{3}{x+3}-\dfrac{x-6}{x^2+3}\)

b, \(\dfrac{2x^2-x}{x-1}+\dfrac{x+1}{1-x}+\dfrac{2-x^2}{x-1}\)

Answer 1

[Thanh Hoàng Thanh]

\(\dfrac{2x^2-x}{x-1}+\dfrac{x+1}{1-x}+\dfrac{2-x^2}{x-1}.\left(x\ne1\right).\)

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