Complete the square for 3x2 - 12x 9.?

To complete the square for the expression (3x^2 - 12x + 9), first factor out the 3 from the first two terms: (3(x^2 - 4x) + 9). Next, to complete the square inside the parentheses, take half of (-4) (which is (-2)), square it (getting (4)), and then adjust the expression: (3(x^2 - 4x + 4 - 4) + 9). This simplifies to (3((x - 2)^2 - 4) + 9), resulting in (3(x - 2)^2 - 12 + 9), or finally (3(x - 2)^2 - 3).