Respuesta :

unicorn3125

Answer:

          AB = 2

Step-by-step explanation:

If B is the midpoint of AC then:

 AB  =  BC

4x - 10 = x - 1

+10         +10

4x  =  x + 9

-x       -x

3x  =  9

÷3      ÷3

x = 3

AB = 4x - 10 = 4×3 - 10 = 12 - 10 = 2