a) \(\left(5x^3-7x^2+x\right):3x^n\)
Để phép tính này chia hết thì
\(\left\{{}\begin{matrix}5x^3⋮3x^n\\-7x^2⋮3x^n\\x⋮3x^n\end{matrix}\right.\Rightarrow n\le1}\)
b) \(\left(13x^4y^3-5x^3y^3+6x^2y^2\right):5x^ny^n\)
Để phép tính này chia hết thì
\(\left\{{}\begin{matrix}13x^4y^3⋮5x^ny^n\\-5x^3y^3⋮5x^ny^n\\6x^2y^2⋮5x^ny^n\end{matrix}\right.\)
\(\left\{{}\begin{matrix}\left\{{}\begin{matrix}n\le4\\n\le3\end{matrix}\right.\\\left\{{}\begin{matrix}n\le3\\n\le3\end{matrix}\right.\\\left\{{}\begin{matrix}n\le2\\n\le2\end{matrix}\right.\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}n\le3\\n\le3\\n\le2\end{matrix}\right.\Rightarrow n\le2}\)
