Select the correct answer. The equation can be solved by completing the square. What number should go in th for the first step? x^2-18x+ldots =4+ 324 81 18 9

To complete the square for the equation , we need to find the number that makes the left side a perfect square trinomial.The general form for a perfect square trinomial is . In this case, we need to find the value of that satisfies the equation.Comparing the given equation with the general form, we can see that . Solving for , we get .Therefore, the number that should go in the blank for the first step is 9.