Answer:
x = 50°
Step-by-step explanation:
Recall that for a triangle, the exterior angle is equal to the sum of its two remove interior angles (also see attached for reference).
in our case, the exterior angle is given as 105° and its two remote interior angles are x and 55°
therefore
105° = 55° + x
x = 105° - 55°
x = 50°
