Hey there!☺
[tex]Answer:\boxed{6}[/tex]
[tex]Explanation:[/tex]
If x is equal to 4, then you will have to multiply 6 by x which is 4.
[tex]6*4=24[/tex]
Now subtract 18 from 24.
[tex]24-18=6[/tex]
[tex]6x-18=6[/tex]
6 is your answer.
Hope this helps!☺