Given the function:

It is a parabola of the form:

Then the parameters of the given parabola are:
a = -7
b = 700
c = 0
We have that if a<0 then the vertex is a maximum value. In this case, a = -7, therefore the function has a maximum.
To find the maximum, we find the coordinate of the vertex, which is given by:

Substitute a and b:

And we find y for the vertex:

The vertex of the parabola is: (50, 17500) therefore the maximum is (50, 17500)
Answer:
maximum: (50, 17500)
minimum: none