How do you find the measure of each

Um, so it's a bit awkward with this question because they actually got the x value incorrect. When they added up all the values, they got 9x - 27 = 180, but it's actually 9x + 27 = 180 because -18 + 45 is positive 27. Anyways, when you solve it correctly you get x = 17, and then you substitute it into the angles. So with 5x - 18, you are saying 5(× 17) - 18 = 67. Then with the other one you do 4(× 17) + 45 = 113. You know that x is definitely 17 because 113 + 67 = 180.