\(\text{Vì }\left(x+1\right)\inƯ\left(x+3\right)\)
\(\Rightarrow\left(x+3\right)⋮\left(x+1\right)\)
\(\Rightarrow\left(x+1+2\right)⋮\left(x+1\right)\)
\(\text{Vì }\left(x+1\right)⋮\left(x+1\right)\text{nên 2⋮(x+1)}\)
\(\Rightarrow\left(x+1\right)\inƯ\left(2\right)\)
\(\RightarrowƯ\left(2\right)=\left\{\pm1;\pm2\right\}\)
Ta có bảng :
x + 1 | 1 | -1 | 2 | -2 |
x | 0 | -2 | 1 | -3 |
\(\Rightarrow x\in\left\{0;-2;1;-3\right\}\)