a) ) \(B=\dfrac{x^2+2x+1}{x^2-1}\) = \(\dfrac{\left(x+1\right)^2}{\left(x+1\right)\left(x-1\right)}\)
ĐKXĐ của x là ( x +1 )(x -1 ) \(\ne0< =>x\ne\pm1\)
b) \(B=\dfrac{\left(x+1\right)^2}{\left(x+1\right)\left(x-1\right)}=\dfrac{\left(x+1\right)}{\left(x-1\right)}\)
c) \(B=\dfrac{x+1}{x-1}=0< =>x=-1\)