a: ĐKXĐ: x<>2; x<>-2
b: \(A=\dfrac{x^2+x\left(x-2\right)+2\left(x-2\right)}{\left(x+2\right)\left(x-2\right)}=\dfrac{x^2+x^2-4}{\left(x+2\right)\left(x-2\right)}\)
\(=\dfrac{2x^2-4}{x^2-4}\)
c: |x|=3 khi x=3 hoặc x=-3
Khi x=3 thì \(A=\dfrac{2\cdot3^2-4}{3^2-4}=\dfrac{2\cdot9-4}{9-4}=\dfrac{14}{5}\)
Khi x=-3 thì A=14/5