Answer: x=9
Step-by-step explanation: Since the triangle appears to be isosceles, both base angles are congruent and the two bottom angles are 7x+2. According to the Exterior Angles Theorem (search it up if you don't know about it), 17x-23 (the exterior angle) must equal the sum of the two remote interior angles, or in this case 2(7x+2), so 17x-23=14x+4, and solving we get x=9.
