[tex]\text{The formula of the midpoint of segment AB:}\\\\\left(\dfrac{x_A+x_B}{2};\ \dfrac{y_A+y_B}{2}\right).\\\\\text{We have the points}\ H(5,\ 13)\ \text{and}\ K(7,\ 5).\ \text{Substitute:}\\\\x=\dfrac{5+7}{2}=\dfrac{12}{2}=6\\\\y=\dfrac{13+5}{2}=\dfrac{18}{2}=9\\\\Answer:\ \boxed{(6,\ 9)}[/tex]