9514 1404 393
Answer:
x = 12
Explanation:
Segment lengths of each chord have the same product.
(x -2)(x +6) = 9×20
x² +4x -12 = 180
x² +4x +4 = 196 . . . . . add 16 (complete the square)
(x +2)² = 14²
x +2 = 14 . . . . . . . . . . . positive root is the only one useful
x = 12