\(3x^2+30x=6000\Leftrightarrow x^2+10x=2000\Leftrightarrow x^2+10x-2000=0\)
\(\Leftrightarrow x^2-40x+50x-2000=0\Leftrightarrow x\left(x-40\right)+50\left(x-40\right)=0\)
\(\Leftrightarrow\left(x+50\right)\left(x-40\right)=0\Leftrightarrow\left\{{}\begin{matrix}x+50=0\\x-40=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=-50\\x=40\end{matrix}\right.\)
vậy phương trình có 2 nghiệm phân biệt \(x=40;x=-50\)