Respuesta :

Answer:

21

Step-by-step explanation:

Since angle ABC is an inscribed angle, its measure is half that of arc AC. Therefore:

[tex]2(3x-1.5)=3x+9 \\\\6x-3=3x+9 \\\\3x-3=9 \\\\3x=12 \\\\x=4 \\\\AC=3(4)+9=12+9=21[/tex]

Hope this helps!