Giải thích các bước giải:
Ta có:
\(\begin{array}{l}
a,\\
\left( {6x - 3} \right)\left( {x - 4} \right) - 6x.\left( {x - 2} \right) = 4\\
\Leftrightarrow \left( {6{x^2} - 24x - 3x + 12} \right) - \left( {6{x^2} - 12x} \right) = 4\\
\Leftrightarrow \left( {6{x^2} - 27x + 12} \right) - \left( {6{x^2} - 12x} \right) = 4\\
\Leftrightarrow 6{x^2} - 27x + 12 - 6{x^2} + 12x = 4\\
\Leftrightarrow - 15x = 4 - 12\\
\Leftrightarrow - 15x = - 8\\
\Leftrightarrow x = \dfrac{8}{{15}}\\
b,\\
{\left( {x - 1} \right)^2} - \left( {x + 1} \right)\left( {x - 1} \right) = 0\\
\Leftrightarrow \left( {x - 1} \right).\left[ {\left( {x - 1} \right) - \left( {x + 1} \right)} \right] = 0\\
\Leftrightarrow \left( {x - 1} \right).\left( { - 2} \right) = 0\\
\Leftrightarrow x - 1 = 0\\
\Leftrightarrow x = 1
\end{array}\)
