Question

Tìm số tự nhiên a biết: (2a+11) chia hết cho (2a+1)

Answer 1

\(\ \ \ \ (2a+11) \vdots (2a+1) \\ \Leftrightarrow (2a+1)+10 \vdots (2a+1) \\ \Leftrightarrow 10 \vdots (2a+1) \\ \Leftrightarrow 2a+1 \in Ư(10) \\ \Leftrightarrow 2a+1 \in \{-10;-5;-2;-1;1;2;5;10\} \\ \Leftrightarrow a \in \begin{Bmatrix} -\dfrac{11}{2};-3;-\dfrac{3}{2};-1;0;\dfrac{1}{2};2;\dfrac{9}{2} \end{Bmatrix} \\ KL:........\)