The formula to calculate the midpoint between two points is given by
[tex]M=(\frac{x_1+x_2}{2},\frac{y_1+y_2}{2})[/tex]we have
M(-19,18)
(x1,y1)=(-13,15)
substitute given coordinates
[tex](-19,18)=(\frac{-13+x_2}{2},\frac{15+y_2}{2})[/tex]step 1
Find out the value of the x2 -coordinate
we have the equation
[tex]\begin{gathered} -19=\frac{-13+x_2}{2} \\ x_2-13=-38 \\ x_2=-38+13 \\ x_2=-25 \end{gathered}[/tex]step 2
Find out the value of the y2-coordinate
we have the equation
[tex]\begin{gathered} 18=\frac{15+y_2}{2} \\ \\ y_2+15=36 \\ y_2=36-15 \\ y_2=21 \end{gathered}[/tex]therefore