mình biết cách làm nhưng nếu mình làm thì bạn phải đó nha!
\(n^2-n+1:n+1\)
\(n+1:n+1\)
\(=>n.\left(n+1\right):n+1\)
\(=>n^2+n:n+1\)
\(=>\left(n^2-n+1\right)-\left(n^2+n\right):n+1\)
\(n^2-n+1-n^2-n:n+1\)
\(\left(n^2-n^2\right)-\left(n+n\right)+1:n+1\)
\(0-2n+1:n+1=>-2n+1:n+1\)
\(n+1:n+1=>2\left(n+1\right):n+1\)
\(=>2n+2:n+1\)
\(=>\left(2n+2\right)+\left(-2n+1\right):n+1\)
\(=>2n+2-2n+1:n+1\)
\(\left(2n-2n\right)+\left(2+1\right):n+1\)
\(3:n+1=>n+1\inƯ\left(3\right)=\left\{1;3;-1;-3\right\}\)
Ta có bảng sau
n+1 | 1 | -1 | 3 | -3 |
n | 0 | -2 | 2 | -4 |
Vậy \(n\in\left\{-4;-2;0;2\right\}\)
!