Question

( x + 5 ) \(⋮\)( x + 2 )

Answer 1

\(\frac{x+5}{x+2}=\frac{x+2+3}{x+2}=\frac{x+2}{x+2}+\frac{3}{x+2}=1+\frac{3}{x+2}\in Z\)

\(\Rightarrow3⋮x+2\)

\(\Rightarrow x+2\inƯ\left(3\right)=\left\{1;-1;3;-3\right\}\)

\(\Rightarrow x\in\left\{-1;-3;1;-5\right\}\)

Answer 2

( x + 5 )
⋮( x + 2 )

x+2+3\(⋮\)x+2

Vì x+2\(⋮\)x+2

Buộc 3\(⋮\)x+2 mà x+2 \(\ge\)2 =>x+2=3

Với x+2=3=>x=1

Vậy x=1