Bao yu is completing the square to solve the polynomial equation.
x2 – x – 3 = 0
what should be her first step?
adding –x to both sides of the equation
adding –3 to both sides of the equation
isolating the first term, x2
isolating the constant, –3

To quote my answer to the question I answered (though you asked it first): 

"The first step of completing the square, regardless of the problem, is making sure that the squared term doesn't have a coefficient. Since that's true for this equation, you isolate the constant, or -3 in this case, which that would be the answer. You'd end up with x^2-x = 3."