Answer :
You would subtract 12 from both sides, resulting in 5x = 60. Then, dividing 5 on both sides, you would have x = 12. Hope this helped! :)
[tex]12+5x=72 \\ -12\ \ \ \ -12 \\ 5x=60 \\ /5\ \ \ \ /5 \\ \boxed{x=12}[/tex]