Answer:
x = 16
Step-by-step explanation:
Given a tangent and a secant from an external point to a circle, then
The product of the external part and the whole of the secant is equal to the square of the tangent, that is
9(9 + x) = 15²
9(9 + x) = 225 ( divide both sides by 9 )
9 + x = 25 ( subtract 9 from both sides )
x = 16
