I think the root of "3x + 1 = 7" is 2...
(n*3)+6-(n*2)=n+3
3n+6-2n=n+3
3n-2n-n=3-6 every n on the left and free numbers on the right
0=-3
contradiction, there are no solution
Hey there!

Your correct answer would be
. . .

Hope this helps.
~Jurgen
The fraction is already in simplest form!:)