Question

determinar as cordenadas do ponto b sabendo que m(-1,-1) é o ponto médio de ab com a(-1,1)

Answer 1

$A=(x_A,y_A)=(-1,1);\ B=(x_B,y_B);\ M=(x_M,y_M)=(-1,-1)\\\\ x_M=\dfrac{x_A+x_B}{2}\ \to\ -1=\dfrac{-1+x_B}{2}\ \to\ -2=-1+x_B\ \to\ \boxed{x_B=-1}\\\\ y_M=\dfrac{y_A+y_B}{2}\ \to\ -1=\dfrac{1+y_B}{2}\ \to\ -2=1+y_B\ \to\ \boxed{y_B=-3}$