a/ $x+7\vdots x-3$
$\leftrightarrow x-3+10\vdots x-3$
$\to 10\vdots x-3$
$\to x-3\in Ư(10)=\{\pm 1;\pm 2;\pm 5; \pm 10\}$
$\to$ Bảng giá trị
$\begin{array}{|c|c|c|}\hline x-3&1&-1&2&-2&5&-5&10&-10\\\hline x&4&2&5&1&8&-2&13&-7\\\hline\end{array}$
b/ $5\vdots x-3$
$\to x-3\in Ư(5)=\{\pm 1;\pm 5\}$
$\to$ Bảng giá trị
$\begin{array}{|c|c|c|}\hline x-3&1&-1&5&-5\\\hline x&4&2&8&-2\\\hline\end{array}$
c/ $24\vdots 2x-1$
$\to 2x-1\in Ư(24)=\{\pm 1;\pm 2;\pm 3;\pm 4;\pm 6;\pm 8;\pm 12;\pm 24\}$
$\to$ Bảng giá trị
$\begin{array}{|c|c|c|}\hline 2x-1&1&-1&2&-2&3&-3&4&-4&6&-6&8&-8&12&-12&24&-24\\\hline 2x&2&0&3&-1&4&-2&5&-3&7&-5&9&-7&13&-11&25&-23\\\hline x&1&0&\dfrac{3}{2}&-\dfrac{1}{2}&2&-1&\dfrac{5}{2}&-\dfrac{3}{2}&\dfrac{7}{2}&-\dfrac{5}{2}&\dfrac{9}{2}&-\dfrac{7}{2}&\dfrac{13}{2}&-\dfrac{11}{2}&\dfrac{25}{2}&-\dfrac{23}{2}\\\hline\end{array}$
d/ $2x+5\vdots x+1$
$\leftrightarrow 2x+2+3\vdots x+1$
$\to 3\vdots x+1$
$\to x+1\in Ư(3)=\{\pm 1;\pm 3\}$
$\to$ Bảng giá trị
$\begin{array}{|c|c|c|}\hline x+1&1&-1&3&-3\\\hline x&0&-2&2&-4\\\hline\end{array}$
