Answer:
Looking at this problem we are given two angles inside of a triangle and we need to determine the measure of x using the third angle inside of the triangle. The first thing that we must do is determine the third angle and we can do this by subtracting the other two angles from 180 because the three angles inside of the triangle add up to it.
Now that we have that angle we need to determine the measure of x. We know that if a line is completely straight then it is 180 degrees. So, we can subtract the angle that we just got from 180 and that will give us the complementary angle.
Therefore, our final answer is that the measure of x is 138.
Hope this helps!