2x(x - 1) - 5x2 = 0
<=> 2x2 - 2x - 5x2 = 0
<=> -2x - 3x2 = 0
<=> -x(2 + 3x) = 0
<=> \(\left[{}\begin{matrix}-x=0\\2+3x=0\end{matrix}\right.\) <=> \(\left[{}\begin{matrix}x=0\\x=-\frac{3}{2}\end{matrix}\right.\)
Vậy \(x=\left\{0;-\frac{3}{2}\right\}\)
\(2x\left(x-1\right)-5x^2=0\)
\(\Leftrightarrow2x^2-2x-5x^2=0\)
\(\Leftrightarrow-2x-3x^2=0\)
\(\Leftrightarrow-x\left(2+3x\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}-x=0\\2+3x=0\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=-\frac{2}{3}\end{matrix}\right.\)
Vậy \(x=\left\{0;-\frac{2}{3}\right\}\)
