Answer:
x=70
Step-by-step explanation:
If we extend the lines we can create an imaginary angle that is directly vertically opposite angle x (see picture for visualisation).
Then, using the rule that alternate interior angles are equal, we can deduct that this new angle is 30+40=70 degrees.
Finally, we know that vertically opposite angles are also equal meaning that x=70 degrees.
Hope this helped!
