Answer:
[tex]\large\boxed{\left(\dfrac{7}{2},\ \dfrac{27}{2}\right)}[/tex]
Step-by-step explanation:
The formula of a midpoint of a segment AB with endpoints at A(x₁, y₁) and B(x₂, y₂):
[tex]M_{AB}\left(\dfrac{x_1+x_2}{2},\ \dfrac{y_1+y_2}{2}\right)[/tex]
We have the points (-3, 9) and (10, 18).
Substitute:
[tex]M(x,\ y)\\\\x=\dfrac{-3+10}{2}=\dfrac{7}{2}\\\\y=\dfrac{9+18}{2}=\dfrac{27}{2}[/tex]