Respuesta :

Answer:

  B = (-17, -29)

Step-by-step explanation:

The midpoint (M) of AB is ...

  M = (A +B)/2

Solving for B gives ...

  B = 2M -A = 2(-9, -10) -(-1, 9) = (-18+1, -20 -9)

  B = (-17, -29)