Verified answer

решение во вложении

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x³ - 0.1x = 0.3x²

x³-0,3x²-0,1x=0 |*10

10x³-3x²-x=0

x(10x²-3x-1)=0

x(10x²-5x+2x-1)=0

x(5x(2x-1)+1(2x-1))=0

x(5x+1)(2x-1)=0

x=0 ∨ x=-1/5 ∨ x=1/2