So to solve this question, your goal is to find out how the way it is solved is not correct.
Your answer would be: On the third line, the student adds the 8 to both sides instead of subtracting. The way the initial equation is given is
y-(-8)=-6(x-2). After distributing the six, the student should make the 8 positive because subtracting a negative makes a positive. After solving, the equation should look like: y(+8)=-6x+12, so you would subtract the 8 from both sides instead of adding it, and solve from there.