Answer:
[tex]x=4.5[/tex]
Step-by-step explanation:
From AAA, both triangles in this figure are similar. Therefore, we can set up the following proportion:
[tex]\frac{x}{9}=\frac{x+3}{15}[/tex] or [tex]\frac{x}{9}=\frac{3}{6}[/tex].
Cross-multiplying, we get:
[tex]6x=9(3),\\6x=27,\\x=\frac{27}{6}=\fbox{$4.5$}[/tex].
