Answer:
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We have intersecting secants here, use relevant theorem:
- If two secant segments are drawn to a circle from an exterior point, then the product of the measures of one secant segment and its external secant segment is equal to the product of the measures of the other secant segment and its external secant segment.
Apply it our question to obtain the following equation:
- (x + 8)*8 = (15 + 9)*9
- 8x + 64 = 216
- 8x = 152
- x = 152/8
- x = 19