Hey there!
[tex]\bold{3n=1; n =4}}[/tex]
[tex]\bold{If\ n=4\ then\ substitute\ where\ the\ n\ is\ at\ in\ your\ equation!}[/tex]
[tex]\bold{3(4)=1}}\\ \bold{3(4)=12}\\\bold{12\neq 1}}\\\\\\\boxed{\boxed{\bold{Answer: 12\neq 1}}}\huge\checkmark[/tex]
Good luck on your assignment and enjoy your day!
[tex]\frak{LoveYourselfFirst:)}[/tex]