There is no solution. Here is the explanation with both of the methods :)
Answer:
x = 29
Step-by-step explanation:
I think this because they give you 78 degrees. The angle across from it (3x - 9) must equal 78 degrees as well. So solve as (3x - 9) = 78. 78 + 9 is 87. 87 divided by 3 is 29.
Hope it helps and is correct!
Answer:
X=30
Step-by-step explanation:
The whole polygon is 360 degrees so:
360-28-40-120-142=X, which is 30
