a) ĐKXĐ : \(x\ne\pm1\)
+ \(B=\left(\frac{\left(x+1\right)^2-\left(x-1\right)^2+\left(x^2-4x-1\right)}{x^2-1}\right)\cdot\frac{x-2014}{x-1}\)
\(B=\frac{4x+x^2-4x-1}{x^2-1}\cdot\frac{x-2014}{x+1}\)
\(B=\frac{x^2-1}{x^2-1}\cdot\frac{x-2014}{x+1}=\frac{x-2014}{x+1}\)\
b) B có giá trị nguyên
\(\Leftrightarrow x-2014⋮x+1\)
\(\Leftrightarrow x+1-2015⋮x+1\)
\(\Leftrightarrow2015⋮x+1\)