For what values of a and c will the graph of f(x) = ax^2 + c have one x-intercept?

The jurassic zoo charges $14 for each adult admission and $5 for each child. the total bill for 77 people from a school trip was $565. how many adults and how many children went to the zoo? i

Ben is three times as old as samantha, who is two years older than half of michel's age. if michel is 12. how old is ben?

Someone this asap for a group of students attends a basketball game. * the group buys x hot dogs at the concession stand for $2 each. * the group buys y drinks at the concession stand for $3 each. the group buys 29 items at the concession stand for a total of $70. how many hot dogs did the group buy?