Answer:
16.6
Step-by-step explanation:
By the property of intersecting secants outside of a circle, we have:
[tex]5 \times (5 + x) = 6 \times (6 + 12) \\ 25 + 5x = 6 \times 18 \\ 25 + 5x = 108 \\ 5x = 108 - 25 \\ 5x = 83 \\ x = \frac{83}{5} \\ x = 16.6[/tex]
