Answer:
x = 6.5
Step-by-step explanation:
By property of intersecting secants outside of circle.
[tex] 6(6 + x) = 5(5 + 10) \\ 36 + 6x = 5 \times 15 \\ 6x = 75 - 36 \\ 6x = 39 \\ x = \frac{39}{6} \\ x = \frac{13}{2} \\ x = 6.5[/tex]
