Answer:
9
Step-by-step explanation:
The product of the secant lengths BC and BD is equal to the square of the tangent length BA.
BC×BD = BA²
3×(3 +x) = 6²
3 +x = 12 . . . . . divide by 3
x = 9 . . . . . . subtract 3
_____
Additional comment
Sometimes the relationships involving secants, tangents, and chords can be difficult to remember. There is basically one rule that applies to all of these geometries:
the product of segment lengths to the circle from the point of intersection of the secants/tangents/chords is the same
A tangent can be thought of as a secant that has a length of 0 between its end points. That is, the two lengths from the point of intersection to the circle are the same.
Here is an example of this rule applied to chords:
https://brainly.com/question/27160911
