Question 100
In the following figure, the center circle $B$ is tangent to the center circle $A$ at $X$. The center circle $C$ is tangent to the center circle $A$ at $Y$. In addition, the center circles $B$ and $C$ are also tangent. If $A B=6, A C=5$ and $B C=9$, how much does $A X$ measure? 