Real roots, a repeated root, or complex roots - with the actual parabola drawn from your numbers, not just the answer.
x = (-b ± √(b²-4ac)) ÷ 2a. Everything about the shape of the answer comes from the discriminant, b²-4ac: positive means the parabola crosses the x-axis twice (two real roots), zero means it just touches the axis at one point (one repeated root, the vertex sits exactly on the x-axis), and negative means the parabola never reaches the x-axis at all - the roots are still mathematically real, just complex numbers, and the graph will show a curve that doesn't cross the horizontal line.
Worked example: x² - 5x + 6 = 0. Discriminant = (-5)² - 4(1)(6) = 25 - 24 = 1. x = (5 ± 1) ÷ 2 = 3 or 2. Try it above - it's the default.