B squared -4ac is the discriminant. you get 0, which means it will have one rational solution.

Two complex solutions.

The discriminant tells you how many solutions there are to an equation The discriminant is b2-4ac For example, two solutions for a equation would mean the discriminant is positive. If it had 1 solution would mean the discriminant is zero If it had no solutions would mean that the discriminant is negative

With the standard notation,

If b2 < 4ac then the discriminant is negative

If b2 = 4ac then the discriminant is zero

If b2 > 4ac then the discriminant is positive

If the discriminant is negative, there are 0 interceptsIf the discriminant is zero, there is 1 interceptIf the discriminant is positive, there are 2 intercepts