Đề là [tex]\frac{-1}{2}x^4y^5.\frac{-1}{3}x^5y^6.....\frac{-1}{99}x^{101}y^{102}[/tex]
= [tex](\frac{-1}{2}.\frac{-1}{3}.....\frac{-1}{99})(x^4x^5....x^{101})(y^5y^6.....y^{102})[/tex]
= [tex]\frac{1}{99!}x^{5145}y^{5243}[/tex]
may tu giai luon di hay la nho anh-xtanh muon biet bai giai thi len bo GD va DT ma hoi co nao may cung bi an dep ma thoi tai vi bai toan nay khong co dap so