Answer:
[tex]\large\boxed{M_{XY}\left(-\dfrac{7}{2};\ \dfrac{3}{2}\right)\to M_{XY}(-3.5,\ 1.5)}[/tex]
Step-by-step explanation:
The formula of a midpoint of AB
[tex]A(x_A,\ y_A),\ B(x_B,\ y_B)\\\\M_{AB}\left(\dfrac{x_A+x_B}{2};\ \dfrac{y_A+y_B}{2}\right)[/tex]
We have the points X(2, -1) and Y(-9, 4).
Substitute:
[tex]M_{XY}\left(\dfrac{2+(-9)}{2};\ \dfrac{-1+4}{2}\right)\\\\M_{XY}\left(\dfrac{-7}{2};\ \dfrac{3}{2}\right)[/tex]