Question

- seja o segmento AB cujo ponto médio P tem abscissa -1 e ordenada -2 sendo B (-5,3) calcule as coordenadas de A.

Answer 1

M(-1,-2)
A(x,y)
B(-5,3)

Xm = ( xa + xb ) / 2

-1 = ( x - 5 ) / 2

-2 = x - 5 

x = 3

Ym = ( ya + yb ) / 2

-2 = ( y + 3 ) / 2

-4 = y + 3 

y = -7

A(3,-7)