Student A added +3x in the fourth line instead of substracting it to cancel the 3x.
The correct solution is:
[tex]3(x+2)+10=6x-2[/tex][tex]3x+6+10=6x-2[/tex][tex]3x+16=6x-2[/tex][tex]3x+16-3x=6x-2-3x[/tex][tex]16=3x-2^{}[/tex][tex]16+2=3x-2+2[/tex][tex]18=3x[/tex][tex]\frac{18}{3}=\frac{3x}{3}[/tex][tex]6=x[/tex]
Then the correct solution to this problem is x=6
