First, divide by 2 and then solve for y. Put into general form. Now, Complete the Square and continue putting into whatever corresponds to .
And before going into Completing the Square, you want to factor part of the right-member expression,
From there, you need to identify the square term to add and subtract in order to perform the rest of the Completing of the Square process.
(Use , and ADD it INSIDE the parentheses and SUBTRACT OUTSIDE the parentheses...)