Assuming the function is y = -1/10 x^2 -5x -1/4 -----------------------(1)
Vertex of a parabola of the form ax^2 +bx +c is (-b/2a,y)
so, x coordinate of vertex = - (-5)/ {2(-1/10)} = -25
putting the value of x-coordinate of vertex in equation (1) we get: y = 62.25
So the vertex = (-25,62.25)
The parabola has maximum at (-25,62.25) and no minimum value. It has a maximum value at vertex because a<0 and no minimum value because it has no lower bound.