To determine the midpoint of a line segment:
The formula to find the mid-point of a line segment give the two end points is:
[tex]M=(\frac{x_1+x_2}{2},\frac{y_2+y_1}{2})[/tex]Where
M is the midpoint and the given points are: ( x₁ , y₁) and ( x₂ , y₂)
Substituting the values from the points in the problem gives:
[tex]\begin{gathered} M=(\frac{x_1+x_2}{2},\frac{y_2+y_1}{2}) \\ M=(\frac{2+9}{2},\frac{-1+9_{}}{2}) \\ M=(\frac{11}{2}\text{ , }\frac{8}{2}) \\ M=(5.5\text{ , 4)} \end{gathered}[/tex]Hence the correct answer for the midpoint M = (5.5 , 4)
