solve for x. show your solution
i’ll mark as brainiest

Answer:
x=12
Step-by-step explanation:
Using the external angle theorem (external angle = sum of interior angles that are NOT adjacent to the external angle you are finding), we can set up an equation...
140=3x+4+8x+4
Start by combining like terms...
140=11x+8
Subtract 8 from both sides
132=11x
Divide both sides by 11
x=12