x = 52
In this question we have 3 lines, where 2 parallel lines intersect the other.
Now, because the 2 lines are parallel, their corresponding angles are congruent. Therfore, we can derive the equation:
First, we need to move 43 to the right side.
Next, we add 9 and 43.
Then, we move x to the left side.
Finally, we subtract the left side.