\(\dfrac{A}{B}=\dfrac{3}{2}x^{n-4}y^{6-n}-\dfrac{5}{2}x^{n-2}y^{4-n}\)
Để A chia hết cho B thì \(\left\{{}\begin{matrix}n-4>=0\\6-n>=0\\n-2>=0\\4-n>=0\end{matrix}\right.\Leftrightarrow n=4\)
=>\(A=3x^3y^6-5x^5y^4;B=2x^3y^4\)
=>\(\dfrac{A}{B}=\dfrac{3}{2}y^2-\dfrac{5}{2}x^2\)