3n+2 chia hết cho n-1
=>3n-3+5 chia hết cho n-1
=>3.(n-1)+5 chia hết cho n-1
=>5 chia hết cho n - 1
=>n-1\(\in\)Ư(5)={-1;1;-5;5}
=>n\(\in\){0;2;-4;6}
CHÚC BẠN HỌC TỐT
NHỚ TICK CHO MÌNH
\(\left(3n+2\right)⋮\left(n+1\right)\)
vì \(\left(n+1\right)⋮\left(n+1\right)\)
=> \(\left(3n+3\right)⋮\left(n+1\right)\)
=> \(\left(3n+2\right)-\left(3n+3\right)⋮\left(x+1\right)\)
=> \(\left(3n+2-3n-3\right)⋮\left(n+1\right)\)
=> \(-1⋮\left(n+1\right)\)
=> \(n=1\inƯ\left(-1\right)=\left\{\pm1\right\}\)
ta có bảng sau
n+1 | -1 | 1 |
n | -2 | 0 |
vậy n=-2 hoăc n=0