Question

The points A(–1, 4), B(5, 2) are the vertices of a triangle of which C(0,–3) is centroid, then the third vertex C is

Answer 1

the third vertex is 2

Answer 2

if (x1,y1), (x2,y2) , (x2,y2) are three vertices of the triangle whose centroid G
G= (x1+x2+x3/3 , y1+y2+y3/3 )

given A (-1,4) , B(5,2) , let third vertex C =(x,y) and G= (0,-3)

(-1+5+x/3, 4+2+y/3) = (0,-3)

(4+x/3 , 6+y/3) =(0,-3)
therefore
4+x/3 = 0  , 6+y/3 = -3
4+x =0     , 6+y = -9

x= -4 , y= -9-6
x= -4 , y = -15

third vertex = C (x,y) = (-4,-15)