For the quadratic equation $a x^{2}+b x+c=0$ the discriminant is $D=$ _____ . The discriminant tells us how many real solutions a quadratic equation has.
If $D>0,$ the equation has _____ real solution (s).
If $D=0,$ the equation has _____ real solution (s)
If $D<0,$ the equation has _____ real solution(s).