Answer:
7
Step-by-step explanation:
Exterior Angle Theorem states that the measure of each exterior angle of a triangle is equal to the sum of the opposite and non-adjacent interior angles.
In this case:
(4x + 7) + (97) = (17x + 13)
4x + 104 = 17x + 13
4x + 91 = 17x
91 = 13x
7 = x