Đáp án:$S={2;0;7;-1;-5;3;-3;4;-2}$
Giải thích các bước giải:
(n-1)(2n+3)=6
⇒n-1; 2n+3∈U(6)={-1;1;-2;2;-3;3;-6;6)
⇒(1)\(\left[ \begin{array}{l}n-1=1\\2n+3=6\end{array} \right.\)⇔ \(\left[ \begin{array}{l}n=2\\n=\frac{3}{2}(loại)\end{array} \right.\)
⇒(2)\(\left[ \begin{array}{l}n-1=-1\\2n+3=-6\end{array} \right.\)⇔ \(\left[ \begin{array}{l}n=0\\n=\frac{-9}{2}(loại)\end{array} \right.\)
⇒(3)\(\left[ \begin{array}{l}n-1=6\\2n+3=1\end{array} \right.\)⇔ \(\left[ \begin{array}{l}n=7\\n=-1\end{array} \right.\)
⇒(4)\(\left[ \begin{array}{l}n-1=-6\\2n+3=-1\end{array} \right.\)⇔ \(\left[ \begin{array}{l}n=-5\\n=-2\end{array} \right.\)
⇒(5)\(\left[ \begin{array}{l}n-1=2\\2n+3=3\end{array} \right.\)⇔ \(\left[ \begin{array}{l}n=3\\n=0\end{array} \right.\)
⇒(6)\(\left[ \begin{array}{l}n-1=-2\\2n+3=-3\end{array} \right.\)⇔ \(\left[ \begin{array}{l}n=-1\\n=-3\end{array} \right.\)
⇒(7)\(\left[ \begin{array}{l}n-1=3\\2n+3=2\end{array} \right.\)⇔ \(\left[ \begin{array}{l}n=4\\n=\frac{-1}{2}(loại)\end{array} \right.\)
⇒(8)\(\left[ \begin{array}{l}n-1=-3\\2n+3=-2\end{array} \right.\)⇔ \(\left[ \begin{array}{l}n=-2\\n=\frac{-5}{2}(loại)\end{array} \right.\)
⇒ $S={2;0;7;-1;-5;3;-3;4;-2}$
