Respuesta :

baabaagreysheep
(180 - 5x + 12) + x + 3x + 8 = 180
180 - x + 20 = 180
-180
-x + 20 = 0
- 20
-x = -20
x = 20
Sorry for the confusion! I believe this is the correct answer
5x+12=3x+8+x(exterior angle property)
5x-4x=8-12
x=-4