The answer is x=51.
We know this by first looking at the exterior angle measure 101 degrees. It has a linear pair so it’s adjacent angle measure is 79 degrees. This means that since the interior angle and exterior angle(79 degrees) share a vertex so they have congruent angle measures
This means the first missing interior angle is 79 degrees
Next the other exterior angle measures 50 degrees and like I said before, it shares a vertex with the other interior angle making the second missing angle 50 degrees
This leads to the final step, adding the angle measures together then subtracting them from 180 degrees.
So 79+50+x=180
79+50 is 129,
Then we subtract 129 from 180 to find x
And your answer is 51 :)
(I hope I explained it clear enough!)