Three roots of the polynomial equation x4- 4x3 - 2x2 + 12x + 9 = 0 are 3. -1 and -1. Explain why the fourth root must be a real number. Find the fourth root.

Can someone explain this in a simple way??

Alocal restaurant advertises that the mode cost of their most popular meals is $8. if the costs of their most popular meals are $7, $8, $8, $12, $13, $15, $17, $18, and $20, which word or phrase best describes this kind of advertising? accurate inaccurate accurate, but misleading inaccurate and misleading