Question

Sendo M (1,-4) o ponto médio de AB e A (1,6) DETERMINE AS COORDENADAS DO PONTO B (XB,YB)

Answer 1

1=(x+1)/2   ==>2=x+1  ==>x=1

-4=(y+6)/2 ==>-8=y+6 ==>x=-14

Answer 2

Boa tarde

A(1,6) e M(1, -4)

(Ax + Bx)/2 = Mx

Ax + Bx = 2Mx
Bx = 2Mx - Ax
Bx = 2*1 - 1 = 1

By = 2My - Ay
By = -8 - 6 = -14 

B(1, -14)