I need help for number 14 can’t figure out the difference

If x=-3 is the only x-intercept of the graph of a quadratic equation, which statement best discribes the discriminant of the equation?

Data was collected on myrtle beach for 11 consecutive days. each day the temperature and number of visitors was noted. the scatter plot below represents this data. how many people visited the beach when the temperature was 84 degrees?

Select a graph that have an equation with a < 0