This is the solution to the problem. If the curve passes through the fixed point, the solution will reach MX+Y = 0 in the penultimate step, and then the axis of symmetry of the parabola passes through the fixed points (0,0) and (18,0) on the X axis. This reference answer is not rigorous enough. There are two points in the calculation result, both of which pass through the origin, so the conclusion is drawn.

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