x² + 10x + 21 = 0
                        ( -7 )

x² - 4x - 45 = 0
                        (    )

x² - 6x - 27 = 0
                        (    )

x² - 10x + 21 = 0
                        (    )

x² + 7x + 10 = 0
                        (    )

x² - 2x - 24 = 0
                        (    )

x² - x - 30 = 0
                        (    )

x² - 7x + 10 = 0
                        (    )

x² - 5x - 24 = 0
                        (    )

x² - 10x + 21 = 0
                        (    )

                      +[    ]

x² - x - 12 = 0
                        (    )

x² - 14x + 48 = 0
                        (    )

x² - 8x + 12 = 0
                        (    )

x² + 5x - 24 = 0
                        (    )

x² + 15x + 54 = 0
                        (    )

x² + 3x - 54 = 0
                        (    )

x² - 2x - 15 = 0
                        (    )

x² + 4x - 12 = 0
                        (    )

x² + 11x + 18 = 0
                        (    )

x² + 14x + 45 = 0
                        (    )

                      +[    ]

x² + 6x - 16 = 0
                        (    )

x² - 2x - 48 = 0
                        (    )

x² - 3x - 18 = 0
                        (    )

x² + 16x + 63 = 0
                        (    )

x² - 8x + 12 = 0
                        (    )

x² - 14x + 48 = 0
                        (    )

x² + 3x - 10 = 0
                        (    )

x² - 3x - 18 = 0
                        (    )

x² - 4x - 12 = 0
                        (    )

x² - x - 20 = 0
                        (    )

                      +[    ]
                 +++[[       ]]