Given points D, C, B and A are colinear (they lie on the same line), you can determine that the slope of AB and the slope of DC are the same.
By definition:
[tex]Slope=\frac{Rise}{Run}[/tex]In this case, you can identify that:
[tex]\begin{gathered} Rise=5 \\ Run=1 \end{gathered}[/tex]Therefore, you can determine that:
[tex]\begin{gathered} Slope\text{ }of\text{ }DC=\frac{5}{1} \\ \\ Slope\text{ }of\text{ }DC=5 \end{gathered}[/tex]Hence, the answer is:
[tex]Slope\text{ }of\text{ }DC=5[/tex]