Can someone please help me I really need help please help me thank you

Answer:
This is modelling the exterior angle formula which states that the measure of an exterior angle is equal to the sum of the measures of its two remote interior angles. Therefore, the answer is x = a + b.
Answer:
x = a+b
Step-by-step explanation:
The exterior angle of a triangle is equal to the sum of the opposite interior angles
x = a+b