Đặt \(x\left(x-2\right)+x-2=0\Leftrightarrow\left(x+1\right)\left(x-2\right)=0\Leftrightarrow x=-1;x=2\)
Đặt \(5x\left(x-3\right)-x+3=0\Leftrightarrow5x\left(x-3\right)-\left(x-3\right)=0\)
\(\Leftrightarrow\left(5x-1\right)\left(x-3\right)=0\Leftrightarrow x=\dfrac{1}{5};x=3\)
Đặt \(x^3-\dfrac{1}{4}x=0\Leftrightarrow x\left(x^2-\dfrac{1}{4}\right)=0\Leftrightarrow x=0;x=\dfrac{1}{2};x=-\dfrac{1}{2}\)
Đặt \(x^2\left(x-3\right)+12-4x=0\Leftrightarrow x^2\left(x-3\right)+4\left(3-x\right)=0\)
\(\Leftrightarrow\left(x^2-4\right)\left(x-3\right)=0\Leftrightarrow x=-2;x=2;x=3\)
f) Ta có: \(x\left(x-2\right)+x-2=0\)
\(\Leftrightarrow\left(x-2\right)\left(x+1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=2\\x=-1\end{matrix}\right.\)
g) Ta có: \(5x\left(x-3\right)-x+3=0\)
\(\Leftrightarrow\left(x-3\right)\left(5x-1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=3\\x=\dfrac{1}{5}\end{matrix}\right.\)
h) Ta có: \(x^3-\dfrac{1}{4}x=0\)
\(\Leftrightarrow x\left(x-\dfrac{1}{2}\right)\left(x+\dfrac{1}{2}\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=\dfrac{1}{2}\\x=-\dfrac{1}{2}\end{matrix}\right.\)
