Using the data of the statement, we make the following diagram:
From the diagram, we see that:
[tex]\begin{gathered} AB=CD, \\ 7y-4=8y-18. \end{gathered}[/tex]Solving this equation for y, we get:
[tex]\begin{gathered} -4=8y-18-7y, \\ -4=y-18, \\ y=18-4, \\ y=14. \end{gathered}[/tex]Answery = 14