Answer:
x=11
Step-by-step explanation:
This is an exterior angle theorem question.
To answer this question, you must know what the exterior angle theorem is:
An exterior angle of a triangle is equal to the sum of the two opposite interior angles. (not my definition)
So first, you need to add the two opposite interior angles.
3x+8+2x+9 is equal to 5x+17.
Then, you make an equation setting 5x+17 equal to the exterior angle.
5x+17 = 8x-16.
To solve this equation, first add 16 on both sides
→5x+33 = 8x
Then, subtract 5x on both sides
→ 33 = 3x
Finally, divide both sides by 3 to get x=11
