\(f\left(x\right)=6x^3+5x^2-5x-2\)
Đặt f(x)=0
\(\Leftrightarrow6x^3+5x^2-5x-2=0\)
\(\Leftrightarrow6x^3+2x^2+3x^2+x-6x-2=0\)
\(\Leftrightarrow\left(3x+1\right)\left(2x^2+x-2\right)=0\)
\(\Leftrightarrow\left(3x+1\right)\left(2x^2+x-2\right)=0\)
hay \(x\in\left\{-\dfrac{1}{3};\dfrac{-1+\sqrt{17}}{4};\dfrac{-1-\sqrt{17}}{4}\right\}\)