You can put this solution on YOUR website!
to find the x coordinate of the vertex, use the formula, x=-b/2a
to find the y-coordinate, substitute -2.7 for x in the given equation
ans: coordinates of the vertex are (-2.7,-42.67)
see the following graph
note: you can also find the coordinates of the vertex by completing the square to come up with the form, y=(x-h)^2+k, with (h,k) being the (x,y) coordinates of the vertex.