Answer:
The coordinates of point B are (6,7).
Step-by-step explanation:
Given points are
Blue = A(-4,8)
Purple = M(1,7.5)
Green = B
It is given that point M is the midpoint of point A and B.
Let coordinates of points are (a,b).
Midpoint of two points is
[tex]Midpoint=(\dfrac{x_1+x_2}{2},\dfrac{y_1+y_2}{2})[/tex]
[tex]M=(\dfrac{-4+a}{2},\dfrac{8+b}{2})[/tex]
Coordinates of midpoint are (1,7.5).
[tex](1,7.5)=(\dfrac{-4+a}{2},\dfrac{8+b}{2})[/tex]
On comparing both sides we get
[tex]1=\dfrac{-4+a}{2}\Rightarrow 2=-4+a\Rightarrow a=6[/tex]
[tex]7.5=\dfrac{8+b}{2}\Rightarrow 15=8+b\Rightarrow b=7[/tex]
Therefore, the coordinates of point B are (6,7).