1.CM

m^3 + 3m^2 - m-3) chia hết cho 48 với m lẻ
2.C/M

n^4 + 6*n^3 + 11* n^2 +6n) chia hết cho 24
Thanks nhìu
1,[TEX]m^3+3m^2-m-3=(m-3)(m-1)(m+1)(1)[/TEX]
do n lẻ\Rightarrow[TEX]n=2k+1[/TEX]
Thay vào (1) dc [TEX]8.k(k+1)(k+2)(2)[/TEX]
Có:[TEX]k(k+1)(k+2)\vdots 2[/TEX]
[TEX]k(k+1)(k+2) \vdots 3[/TEX]
[TEX](2;3)=1[/TEX]
\Rightarrow[TEX]k(k+1)(k+2) \vdots 6[/TEX]
\Rightarrow[TEX](2) \vdots 48[/TEX]
\RightarrowDPCM
2.[TEX]n^4+6n^3+11n^2+6n=n(n+1)(n+2)(n+3)[/TEX]
[TEX]n(n+1)(n+2)(n+3) \vdots 8[/TEX]
[TEX]n(n+1)(n+2)(n+3) \vdots 3[/TEX]
[TEX](3;8)=1[/TEX]
\Rightarrow[TEX]n^4+6n^3+11n^2+6n \vdots 24[/TEX]