Which of the following equations result in a parabola graph?

a) [[$ y = -3x^2 + 9x $]]

Answer: [[$ y = -3x^2 + 9x $]] is is not the parabola equation.

b) [[$ y = -0,25x^2 -0,73 $]]

Answer: [[$ y = -0,25x^2 -0,73 $]] is is not the parabola equation.

c) [[$ y = x(3 + x) $]]

Answer: [[$ y = x(3 + x) $]] is is not the parabola equation.

d) [[$ y = x( x^2 - 2x) $]]

Answer: [[$ y = x( x^2 - 2x) $]] is is not a parabola equation.