Respuesta :

Vertical angles are where the top equals the bottom or the left equals the right angle. So we would do:
8x - 13 = 5x + 8
And then substitute.
3x = 21
x = 7
juraijsaeed

Answer:

8x-13=5x+8

8x-5x=13+8

3x=21

x=21/3

x=7