Tangents to a circle that intersects at a point are equal in length.
Therefore,
|AB| = |AC|
Where
|AC| is the length of line AC
and
|AB| is the length of line AB
Hence,
[tex]\begin{gathered} 4x+2=2x+8 \\ \text{this implies that} \\ 4x-2x=8-2 \\ 2x=6 \\ \text{Dividing both sides by 2, we have} \\ \frac{2x}{2}=\frac{6}{2} \\ \text{thus} \\ x=3 \end{gathered}[/tex]x = 3 units