What is the answer to this?

Answer: J
Step-by-step explanation:
Corresponding sides of similar triangles are proportional, so
[tex]\frac{3x-9}{x+8}=\frac{45}{30}=\frac{3}{2}\\\\2(3x-9)=3(x+8)\\\\6x-18=3x+24\\\\3x-18=24\\\\3x=42\\\\x=14\\\\\implies YX=14+8=22[/tex]