Question 83533
Did you find the value of the discriminant ({{{b^2-4ac}}})?
{{{b^2-4ac = (-50)^2-4(5)(125)}}}={{{2500-2500 = 0}}}
The discriminant is zero: The solution has one real root, a double root.
This means that the curve (parabola) represented by the quadratic equation does not actually cross the x-axis, but just touches (abuts) the x-axis as you can see in the graph:
{{{graph(300,200,-5,20,-8,150,5x^2-50x+125)}}}