Đáp án:
Ta có: f(x)= $3x^{2}$ -$9x^{}$ + $2x^{}$-$6^{}$ =0
⇔ $3x^{}$$(x-3)^{}$ + $2^{}$$(x-3)^{}$ =0
⇔$(x-3)^{}$$(3x+2)^{}$ = 0
⇔\(\left[ \begin{array}{l}x-3=0\\3x+2=0\end{array} \right.\)
⇔\(\left[ \begin{array}{l}x=3\\x= -\frac{2}{3}\end{array} \right.\)