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x in (-oo:+oo)
-(x*((x-0.393)/999)) = 393 // - 393
-(x*((x-0.393)/999))-393 = 0
(-1*x*(x-0.393))/999-393 = 0
(-1*x*(x-0.393))/999+(-393*999)/999 = 0
-1*x*(x-0.393)-393*999 = 0
0.393*x-x^2-392607 = 0
0.393*x-x^2-392607 = 0
0.393*x-x^2-392607 = 0
DELTA = 0.393^2-(-392607*(-1)*4)
DELTA = 0.393^2-1570428
DELTA = -1570427.845551
DELTA < 0
1 = 0
1/999 = 0
1/999 = 0 // * 999
1 = 0
x belongs to the empty set
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