\(=\dfrac{-8xy\left(1-3x\right)^3:4x\left(1-3x\right)}{12x^3\left(1-3x\right):4x\left(1-3x\right)}=\dfrac{-2y\left(1-3x\right)^2}{3x^2}\)
\(\dfrac{8xy\left(3x-1\right)^3}{12x^3\left(1-3x\right)}=\dfrac{-2y\left(1-3x\right)^3}{3x^2\left(1-3x\right)}=\dfrac{-2y\left(1-3x\right)^2}{3x^2}\)