{x²-5x≥0⇒x(x-5)≤0⇒x≤0 U x≥5
{x²-5x>16
x²-5x-16>0
D=25+64=89
x1=(5-√89)/2
x2=(5+89)/2
x<(5-√89)/2 U x>(5+√89)/2
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-----------((5-√89)/2)-----[0]-----------[5]-------((5+√89)/2)--------------------
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x∈(-∞;(5-√89)/2) U ((5+√89)/2;∞)