Bài 3:
a: \(=\dfrac{x-2+x}{2x-4}=\dfrac{2x-2}{2x-4}=\dfrac{x-1}{x-2}\)
b: \(=\dfrac{6}{5\left(x-4\right)}-\dfrac{x-5}{\left(x-4\right)^2}\)
\(=\dfrac{6x-24-5x+25}{5\left(x-4\right)^2}=\dfrac{x+1}{5\left(x-4\right)^2}\)
c: \(=\dfrac{3x+2-12x+8+3x-6}{\left(3x-2\right)\left(3x+2\right)}=\dfrac{-6x+4}{\left(3x-2\right)\left(3x+2\right)}=\dfrac{-2}{3x+2}\)