Lê Quốc Trần Anh Coordinator
11/07/2017 at 09:54-
\(\dfrac{2n+8}{n+2}=\dfrac{2\left(n+2\right)+4}{n+2}=2+\dfrac{4}{n+2}\)
\(\dfrac{2n+8}{n+2}\in N\) only when \(\dfrac{4}{n+2}\in N\) or \(4⋮n+2\)
Since \(n\in N,n\ge0\)and \(n+2\ge2\).So n + 2 = 2 or n + 2 = 4
=> n = 0 or n = 2
Lê Quốc Trần Anh selected this answer. -
FA KAKALOTS 28/01/2018 at 22:15
n+8n+2=2(n+2)+4n+2=2+4n+2
2n+8n+2∈N
only when 4n+2∈N or 4⋮n+2
Since n∈N,n≥0
and n+2≥2
.So n + 2 = 2 or n + 2 = 4
=> n = 0 or n = 2