Discriminant is b²-4ac in a quadratic equation Ax²+ Bx+C=0.
If the value of discriminant is less than zero, then the equation has two complex solutions
If the value of the discriminant is equal to zero, then the equation has one solution
If the value of the discriminant is more than zero, then there will be two real solutions.
Just plug in your values and you'll get the right answers.