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I'd like to shade the region defined in the xy-plane produced by this code:

In[305]:= Reduce[-x^4 + x^2 (x + y)^2 > 0, x]

Out[305]= (y < 0 && (x < 0 || 0 < x < -(y/2))) || (y > 
    0 && (-(y/2) < x < 0 || x > 0))

Is there an easy way to do this?

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epxr = -x^4 + x^2 (x + y)^2 > 0;
reg = Reduce[expr, x]; 

RegionPlot[reg, {x, -10, 10}, {y, -10, 10}]
(* or RegionPlot[expr, {x, -10, 10}, {y, -10, 10}] *)

enter image description here

or

ParametricPlot[{x, y}, {x, -10, 10}, {y, -10, 10}, Mesh -> None, 
 RegionFunction -> Function[{x, y}, reg], Axes -> False , PlotPoints -> 100]
(* same picture -- almost *)
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sol = Reduce[-x^4 + x^2 (x + y)^2 > 0, x]

(y < 0 && (x < 0 || 0 < x < -(y/2))) || (y > 0 && (-(y/2) < x < 0 || x > 0))

RegionPlot[ImplicitRegion[sol, {x, y}]]

enter image description here

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