Question

Answer 1

a: \(B=\dfrac{x\left(x-1\right)^2}{x^2+1}:\left[\left(1+x+x\right)\left(\dfrac{1+x^2-x-x^2}{1+x}\right)\right]\)

\(=\dfrac{x\left(x-1\right)^2}{x^2+1}:\left(2x+1\right)\left(\dfrac{-x+1}{x+1}\right)\)

\(=\dfrac{x\left(x-1\right)^2}{x^2+1}\cdot\dfrac{\left(x+1\right)}{-\left(x-1\right)\left(2x+1\right)}\)

\(=\dfrac{x\left(x-1\right)\left(x+1\right)}{-\left(x^2+1\right)\left(2x+1\right)}\)

b: Đề sai nha bạn, ví dụ x>1 thì B đâu có lớn hơn 0