We will use the formula;
(Xm , Ym) = (x₁ + x₂ /2 , y₁ + y₂ /2)
This implies that;
Xm = x₁ + x₂ /2
Fom the question, Xm = 4 Ym=2 x₁ =6 y₁=-4
substituting the values into;
Xm = x₁ + x₂ /2 and then solve for x₂
4 = 6+x₂ /2
multiply both-side of the equation by 2
8 = 6 + x₂
subtract 6 from both-side of the equation
2 =x₂
x₂=2
Similarly, substituting the values into;
Ym = y₁ + y₂ /2 and then solve for y
2 = -4 +y₂ /2
multiply both-side of the equation by 2
4 = -4 +y₂
add 4 to both-side of the equation
8 = y₂
y₂ = 8
Hence the coordinates of B are (2 ,8)