To solve this equation for x, we need to subtract 6 from both sides of the equation as follows:
[tex]\begin{gathered} y=x+6\Rightarrow y-6=x+6-6_{} \\ y-6=x+0 \\ x=y-6 \end{gathered}[/tex]Therefore, if we solve for x, we get x = y - 6 (third option).
In summary, we have that:
[tex]x=y-6[/tex][Third option.]