Some one please help me with these questions I’m struggling :(

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

Lee has $1.75 in dimes and nickels. the number of nickels is 11 more than the number of dimes. how many of each coin does he have?

Use the data on the dot plot to answer the question.how many people read for more than three hours last week? i'm on a unit test review