You are looking at a pair of parallel lines (a and b) and a transversal that crosses them both.
Now that you know what think back to when you learned the relationship between angles formed by a transversal and a set of parallel lines.
You can have same side exterior, same side interior, alternate interior and alternate exterior. Which set of these are these angles?
Remember same side interior and same side exterior angles are supplementary (they have a sum of 180 degrees). Alternate interior and alternate exterior angles are congruent. Knowing this how can an equation be written using the expressions in the image?
Since these two angles are opposite exterior angles, they are equivalent. that means that 5x - 2/3 = 3 1/3x + 5, from here you should simplify the terms so you have all of x on one side and all of the number on ther other, it should be 1 2/3x = 5 2/3, then all you have to do is divide both sides by 1 2/3 to get x which is 3.4 or 3 2/5
