Question

giúp mk, mk tick cho

Answer 1

b) ĐKXĐ: \(n\ne-\dfrac{1}{3}\left(đúng.do.n\in Z\right)\)

 \(\dfrac{6n-2}{3n+1}=2-\dfrac{4}{3n+1}\in Z\)

\(\Rightarrow\left(3n+1\right)\inƯ\left(4\right)=\left\{-4;-2;-1;1;2;4\right\}\)

Do \(n\in Z\Rightarrow n\in\left\{-1;0;1\right\}\)

c) ĐKXĐ: \(n\ne2\)

\(\dfrac{n^2-3n+5}{n-2}=\dfrac{\left(n-2\right)\left(n-1\right)+3}{n-2}=n-1+\dfrac{3}{n-2}\in Z\)

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

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