Discover Questions

I got part A but I don't know why b and c wont get me the right answer can someone explain? What can I expect from the Planet Parade that started on July 4th? Is Brazil the largest country in South Africa ? Consider the roots of the equation.
Find the conditions for exactly one root (double root) for the equation y=x^2+bx+c? What US state has the most severe thunderstorms? That produce tornadoes!?