[tex]A(x_A;\ y_A);\ B(x_B;\ y_B)\\\\midpoint\ of\ AB\ \left(\dfrac{x_A+x_B}{2};\ \dfrac{y_A+y_B}{2}\right)\\---------------------\\\\A(-11;\ 34);\ B(47;\ 0)\\\\midpoint\ of\ AB:\left(\dfrac{-11+47}{2};\ \dfrac{34+0}{2}\right)=\left(\dfrac{36}{2};\ \dfrac{34}{2}\right)\\\\\boxed{\boxed{(18;\ 17)}}[/tex]
