Answer:
x=50
Step-by-step explanation:
The Intersecting Secant-Tangent Theorem states that if a secant and tangent line intersect outside of a circle, then
(length of the tangent line)² = (length of secant line from outside the circle to touching it) * (part of secant that is a chord). In this example, we can say that
30² = 18 * x
900 = 18 * x
divide both sides by 18 to isolate x
x=50
