If using the method of completing the square to solve the quadratic equation x2 + 20x – 6 = 0, which number would have to be
added to "complete the square"?

David is spreading mulch on a triangular area of his flower bed. the coordinates of the vertices of the area are (1, 3), (9, 3), and (4, 6). what is the area of the triangle if each square has an area of 3 square feet?