We have the following equations:
[tex]\begin{gathered} x=d+2 \\ d+2+x=y \end{gathered}[/tex]notice that we can substitute d+2 on the second equation with x to get the following:
[tex]\begin{gathered} (d+2)+x=y \\ \Rightarrow x+x=y \\ \Rightarrow2x=y \end{gathered}[/tex]therefore, the statement that is true is y = 2x
