Respuesta :

9514 1404 393

Answer:

  d.  AB = 54

Step-by-step explanation:

The triangle is isosceles, so AB = AC.

  (4x +6) = (5x -6)

  12 = x . . . . . . . . . . . . add 6-4x to both sides

Then the length of AB is ...

  AB = 4x +6 = 4(12) +6 = 48 +6

  AB = 54