а) 2xy-6y^2=<span>-2y*(3y-x)</span>
б) a^3-4a=<span>(a-2)*a*(a+2)</span>
а) a^2b-ab^2=<span>-ab*(b-a)</span>
б) 9x-x^3=<span>(3-x)*x*(x+3)</span>
(a+1)(a²-a+1)-a(a+1)≥0
(a+1)(a²-a+1-a)≥0
(a+1)(a²-2a+1)≥0
(a+1)(a-1)²≥0
a=-1 a=1
_ + +
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-1 1
a∈[-1;∞)
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