Question

0,2x(x-3)=(x-3)(1,8-3)

Answer 1

\(\Leftrightarrow\dfrac{x}{5}\left(x-3\right)-\left(x-3\right)\left(-\dfrac{6}{5}\right)=0\)

\(\Leftrightarrow\left(x-3\right)\left(\dfrac{x}{5}+\dfrac{6}{5}\right)=0\)

\(\Leftrightarrow\left(x-3\right)\left(\dfrac{x+6}{5}\right)=0\)

\(\Leftrightarrow\left\{{}\begin{matrix}x-3=0\\\dfrac{x+6}{5}=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=0+3\\x=\left(0:5\right)-6\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=3\\x=-6\end{matrix}\right.\)