Ta có
3(x3-x2-x)=1
(=) 3x3 - 3x2 - 3x =1
(=) 4x3 - x3 -3x2 -3x =1
(=) 4x3 = x3 +3x2 +3x +1
(=) 4x3 = (x+1)3
=> x=\(\frac{x+1}{\sqrt[3]{4}}\)
=> x-\(\frac{x}{\sqrt[3]{4}}=\frac{1}{\sqrt[3]{4}}\)
=> x(1-\(\frac{1}{\sqrt[3]{4}}\)) =\(\frac{1}{\sqrt[3]{4}}\)
=> x \(\frac{\sqrt[3]{4}-1}{\sqrt[3]{4}}=\frac{1}{\sqrt[3]{4}}\)
=> x =\(\frac{1}{\sqrt[3]{4}-1}\)