Respuesta :

Explanation

Triangles ABC and CDE are congruent, then:

[tex]\begin{gathered} \frac{15-x}{20}=\frac{x}{5} \\ 5(15-x)=20x \\ 75-5x=20x \\ 75=20x+5x \\ 75=25x \\ \frac{75}{25}=x \\ 3=x \end{gathered}[/tex]

Answer

x=3