Complete the square to write
Make two perfect squares. 2 generic rectangles squares, each with interior labeled as follows: top left, x squared, top right & bottom left, each labeled 3, x. Bottom right blank. To the right of the second square is the label, negative 7.
Added to the squares, top side & left side, on each, labeled, x, + 3. Interior bottom right each labeled, 9. After the negative 7, is the label negative 18.