I will assume you meant y=-10(x^2)+20x-15 In which case to find the vertex you would do -b/2a So for this one that would be -20/-20 which is just 1, that is the x value of the vertex so to find the y value you plug 1 into the equation and get 5 so the Vertex is (1,5) Since the a value is negative the equation will have a max value and that value will be the same as the y value of the vertex. Max value: y=5 Axis of symmetry is the x value of the vertex Axis of symmetry: x=1 The range is all possible y values so in this case it is from the y value of the vertex and down Range: {y|y<5} Domain is all possible x values which is all real numbers for every quadratic.
In summary: Vertex is (1,5) Axis of symmetry: x=1 Max value: y=5 Range: {y|y<5} Domain: all real numbers
