\(5x\left(1-2x\right)-3x\left(x+18\right)=0\)
\(\Leftrightarrow5x-10x^2-3x^2-54x=0\)
\(\Leftrightarrow-13x^2-49x=0\)
\(\Leftrightarrow x\left(-13x-49\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\-13x-49=0\Rightarrow x=-\dfrac{49}{13}\end{matrix}\right.\)
Vậy pt có 2 nghiệm là....
Ta có\(5x\left(1-2x\right)-3x\left(x+18\right)=0\)
\(\Leftrightarrow\)\(5x-10x^2-3x^2-54x=0\)
\(\Leftrightarrow-13x^2-49x=0\)
\(\Leftrightarrow x\left(-13x-49\right)=0\)
\(\Leftrightarrow\)\(\left[{}\begin{matrix}x=0\\-13x-49=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\-13x=49\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\x=-\dfrac{49}{13}\end{matrix}\right.\)
