`20x^3 - 15x^2 + 7x = 45x^2 - 38x`
`<=> 20x^3 - 15x^2 - 45x^2 + 38x + 7x = 0`
`<=> 20x^3 - 60x^2 + 45x = 0`
`<=> 4x^3 - 12x^2 + 9x = 0`
`<=> x(4x^2 - 12x + 9) = 0`
`<=> x(2x - 3)^2 = 0`
`<=>` \(\left[ \begin{array}{l}x = 0\\2x - 3 = 0\end{array} \right.\)
`<=>` \(\left[ \begin{array}{l}x = 0\\x = \dfrac{3}{2}\end{array} \right.\)