Answer:
x = 12
Step-by-step explanation:
If the triangle are similar, then the sides are in proportion:
[tex]\dfrac{x}{18}=\dfrac{15}{15+7.5}[/tex]
[tex]\dfrac{x}{18}=\dfrac{15}{22.5}[/tex] cross multiply
[tex]22.5x=(18)(15)[/tex]
[tex]22.5x=270[/tex] divide both sides by 22.5
[tex]x=12[/tex]
