ĐKXĐ : \(x\ne-1,x\ne5\)
Ta có : \(\frac{2x^2-20x+50}{3x+3}\cdot\frac{x^2-1}{4\left(x-5\right)^2}\)
\(=\frac{2\left(x^2-10x+25\right)}{3\left(x+1\right)}\cdot\frac{\left(x+1\right)\left(x-1\right)}{4\left(x-5\right)^2}\)
\(=\frac{2\left(x-5\right)^2}{3\left(x+1\right)}\cdot\frac{\left(x+1\right)\left(x-1\right)}{4\left(x-5\right)^2}\)
\(=\frac{x-1}{6}\)