Respuesta :

Answer:

If M is the midpoint of AB, then MB is half of AB:

6x + 40 = 2(2x - 30)

6x + 40 = 4x - 60

-4x          -4x

2x + 40 = -60

     -40     -40

2x/2 = -100/2

x = -50

AB = 6(-50) + 40 = -300 + 40 = -260

MB = 2(-50) - 30 = -100 - 30 = -130