Answer: x = -7
Step-by-step explanation:
The missing angle between the 107 and (4-2x) is 55 due to the vertical angles theorem.
The three angles mentioned add to 180 because they form a straight line.
Here's what the steps would look like:
107+55+(4-2x) = 180
166-2x = 180
-2x = 180-166
-2x = 14
x = 14/(-2)
x = -7