Since angles ACB and ECD are vertical angles, they are congruent, so we have
Calculating the sum of internal angles in triangle ABC, we have:
[tex]\begin{gathered} ABC+ACB+CAB=180 \\ ABC+52+63=180 \\ ABC=180-52-63 \\ ABC=65 \end{gathered}[/tex]
Since triangles ACB and DCE are congruent, we have [tex]\begin{gathered} DEC=ABC \\ 5x=65 \\ x=13 \end{gathered}[/tex]
