Immediately, you can get rid of the 1/5x and -1/5x because they would cancel each other out which leaves you with:
[tex]7 \frac{2}{3} = \frac{2}{3} [/tex]
From there you can subtract 2/3 from each side and get 7.
I still believe something is wrong with the equation since it still doesnt, make sense but since you swear that is the correct equation...