Answer:
The equation you could use is the 3rd solution. You need to add all of the nubers that have an x after it because you can't add a number that doesn't have x and a number that does have x. So once you add all of those, you add the 10, and keep the subtrction symbol instead of the addition symbol. And like I said before, all triangles are equal to 180.
Step-by-step explanation:
