Relax

Respuesta :

39=9x+7-3x+20

Subtract 27 from each side

12=6x
2=x

Now plug in 2 for x to find AB and BC

9x+7= AB
9(2)+7=AB
18+7= AB
25= AB

-3x+20= BC
-3(2)+20= BC
-6+20= BC
14= BC