\(\left(x-100\right)\left(x-99\right)\left(x-98\right)...\left(x-2\right)\left(x-1\right)=0\\ \Rightarrow\left\{{}\begin{matrix}x-1=0\\x-2=0\\...\\x-100=0\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=1\\x=2\\...\\x=100\end{matrix}\right.\)
\(\Rightarrow\) Biểu thức \(\left(x-100\right)\left(x-99\right)\left(x-98\right)...\left(x-1\right)=0\) khi \(1\le x\le100\)