Question

bài 1 : Rút gọn

8) x+3/x^2-3x

9) x-2/x-5÷(x-2)^2/x^2-25

10) 1÷(1-1/a)

11) (a+6/3a+9-1/a+3)÷a+2/27a

12) 6x+6/3x^2+3x

13) 3/x+3 -x-6/x^2+3x

14) (x/x+2+2/x-2+4x/x^2-4)×x^2-2x+4/x+2

Answer 1

Bài 1: 

8: \(=\dfrac{x+3}{x\left(x-3\right)}\)

9: \(=\dfrac{x-2}{x-5}\cdot\dfrac{\left(x-5\right)\left(x+5\right)}{\left(x-2\right)^2}=\dfrac{x+5}{x-2}\)

10: \(=1:\dfrac{a-1}{a}=\dfrac{a}{a-1}\)

12: \(=\dfrac{6\left(x+1\right)}{3x\left(x+1\right)}=\dfrac{2}{x}\)

13: \(\dfrac{3}{x+3}-\dfrac{x-6}{x\left(x+3\right)}\)

\(=\dfrac{3x-x+6}{x\left(x+3\right)}=\dfrac{2x+6}{x\left(x+3\right)}=\dfrac{2}{x}\)