find an $x^{\prime} y^{\prime}$-equation for the graph of the given $x y$-equation so that the center or, in the case of a parabola, the vertex, of the graph is at the origin in the $x^{\prime} y^{\prime}$-system. Sketch the curve, showing both sets of coordinate axes, and identify the type of curve.
$8 x-y^2-8 y=0$