\(=\frac{\left(2x-4\right)\left(2x+4\right)}{\left(1-x\right)^2}.\frac{1-x}{3x-6}=\frac{\left(2x-4\right)\left(2x+4\right)}{\left(1-x\right)\left(3x-6\right)}\)
\(\frac{4x^2-16}{1-2x+x^2}:\frac{3x-6}{1-x}\)
\(=\frac{4x^2-16}{1-2x+x^2}\cdot\frac{1-x}{3x-6}\)
\(=\frac{4\left(x^2-4\right)}{\left(1-x\right)^2}\cdot\frac{1-x}{3\left(x-2\right)}\)
\(=\frac{4\left(x-2\right)\left(x+2\right)}{\left(1-x\right)^2}\cdot\frac{1-x}{3\left(x-2\right)}\)
\(=\frac{4\left(x-2\right)\left(x+2\right)\left(1-x\right)}{\left(1-x\right)^2\cdot3\left(x-2\right)}\)
\(=\frac{4\left(x+2\right)}{3\left(1-x\right)}\)
