Answer:
x = 8
Explanation:
This is not an actual geometry task, it's just algebra:
The sum of angles in a triangle is 180° and that's the only thing we're gonna use.
103 + 4x + (5x + 5) = 180
4x + (5x + 5) = 180 - 103
9x + 5 = 77
9x = 77 - 5 = 72
x = 72 / 9 = 8