\(\left(2x+1\right)⋮\left(x+2\right)\)
vì \(\left(x+2\right)⋮\left(x+2\right)\)
=> \(2\left(x+2\right)⋮\left(x+2\right)\)
=> \(\left(2x+4\right)⋮\left(x+2\right)\)
=> \(\left(2x+1\right)-\left(2x+4\right)⋮\left(x+2\right)\)
=> \(\left(2x+1-2x-4\right)⋮\left(x+2\right)\)
=> \(-3⋮\left(x+2\right)\)
=> \(x+2\inƯ\left(-3\right)=\left\{\pm1;\pm3\right\}\)
ta có bảng sau
x+2 | -3 | -1 | 1 | 3 |
x | -5 | -3 | -1 | 1 |
vậy ...