Question

3n-13 chia hết 3n+2

Làm giúp mình nhé. Cảm ơn các bạn

Answer 1

\(\left(3n-13\right)⋮\left(3n+2\right)\)\(\Leftrightarrow\left(3n+2\right)-15⋮\left(3n+2\right)\)

Vì \(\Leftrightarrow\left(3n+2\right)⋮\left(3n+2\right)\) nên \(\Leftrightarrow15⋮\left(3n+2\right)\)

\(\Leftrightarrow\left(3n+2\right)\in U\left(15\right)\)\(\Leftrightarrow\left(3n+2\right)\in\left\{-15;-5;-3;-1;1;3;5;15\right\}\)

\(\Leftrightarrow3n\in\left\{-17;-7;-5;-3;-1;1;3;12\right\}\)

\(\Rightarrow n\in\left\{-\frac{17}{3};-\frac{7}{3};-\frac{5}{3};-1;-\frac{1}{3};\frac{1}{3};1;4\right\}\)

KL: .....................................