Sửa đề \(\left(x-3\right)\left(x^2+3x+9\right)+x\left(x+2\right)\left(2-x\right)=1\)
\(\Rightarrow x^3-3^3-x\left(x+2\right)\left(x-2\right)=1\)
\(\Rightarrow x^3-27-x\left(x^2-2^2\right)=1\)
\(\Rightarrow x^3-27-x^3+4x=1\)
\(\Rightarrow4x=1+27\)
\(\Rightarrow4x=28\)
\(\Rightarrow x=7\)