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5.33 = (1000/3)*x^2+3900*x+100 // - (1000/3)*x^2+3900*x+100
5.33-((1000/3)*x^2)-(3900*x)-100 = 0
(-1000/3)*x^2-3900*x-100+5.33 = 0
-1000/3*x^2-3900*x-94.67 = 0
DELTA = (-3900)^2-(-1000/3*(-94.67)*4)
DELTA = 15083773.3333345956
DELTA > 0
x = (15083773.3333345956^(1/2)+3900)/(-1000/3*2) or x = (3900-15083773.3333345956^(1/2))/(-1000/3*2)
x = -3/2000*(15083773.3333345956^(1/2)+3900) or x = -3/2000*(3900-15083773.3333345956^(1/2))
x in { -3/2000*(15083773.3333345956^(1/2)+3900), -3/2000*(3900-15083773.3333345956^(1/2)) }
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