Respuesta :

Answer:

x = 6 , AC = [tex]\sqrt{89}[/tex]

Step-by-step explanation:

(3)

Tangents to a circle from an external point are congruent, then

4x - 9 = 15 ( add 9 to both sides )

4x = 24 ( divide both sides by 4 )

x = 6

(4)

the angle between a tangent and a radius at the point of contact is right , so

Δ ABC is a right triangle with hypotenuse AC

Using Pythagoras' identity in the right triangle

AC² = AB² + BC² = 5² + 8² = 25 + 64 = 89 ( square root both sides )

AC = [tex]\sqrt{89}[/tex] ≈ 9.4 ( to 1 dec. place )