Answer:
Ok, we know that we have a parabola (a quadratic equation) that is concave down.
This means that the "arms" of the graph will go down, then, the vertex is the maximum of the parabola.
Now we know that the vertex (again, the maximum) is on the third quadrant, this quadrant is on the negative region of x and on the negative region of y.
So, if from this point the arms of the parabola go down, then the arms will never intersect the x-axis.
So we do not have x-axis intercepts, which means that this parabola as no real roots.
And a parabola has always a y-intercept, but we have no enough information to conclude which is the y-intercept.
