If using the method of completing the square to solve the quadratic equation x2-6x-260x and 82032 and 8203 and 8203 and minus6x and minus260 which number would have to be added to complete the square?

To complete the square for the quadratic equation (x^2 - 6x), you take half of the coefficient of (x) (which is (-6)), square it, and add that value. Half of (-6) is (-3), and squaring it gives (9). Therefore, you would need to add (9) to complete the square.