Question

mn giúp mik dc ko ạ

 

Answer 1

1: \(=\dfrac{4\left(x-1\right)}{\left(x+1\right)^2}\cdot\dfrac{3\left(x+1\right)}{-20\left(x-1\right)}=\dfrac{-12}{20}\cdot\dfrac{1}{x+1}=\dfrac{-3}{5x+5}\)

2: \(=\dfrac{x^2-xy+y^2}{\left(x-y\right)\left(x+y\right)}\cdot\dfrac{\left(x-y\right)^2}{\left(x+y\right)\left(x^2-xy+y^2\right)}\)

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

3: \(=\dfrac{1-4x^2-1}{1-2x}:\dfrac{4x^2-2x-4x^2}{2x-1}\)

\(=\dfrac{4x^2}{2x-1}\cdot\dfrac{2x-1}{-2x}\)

=-2x