Point a is at (-2,4) => (x1,y1)
Midpoint is (2.5, 3.5) => (a,b)
Point B is (x2, y2)
To find midpoint we use formula
a= 2.5, b= 3.5, x1= -2 and y1= 4
Plug in all the values and findout x2, y2
multiply 2 on both sides to remove fraction
(5 = -2+x2 , 7 = 4+ y2)
5 = -2+x2, so x2= 7
7 = 4+ y2, so y2= 3
The point B is ( 7, 3)