\(x^4-x^3+x^2+2\)
\(=\left(x^4+x^3+x^2\right)-\left(2x^3+2x^2+2x\right)+\left(2x^2+2x+2\right)\)
\(=x^2\left(x^2+x+1\right)-2x\left(x^2+x+1\right)+2\left(x^2+x+1\right)\)
\(=\left(x^2-2x+2\right)\left(x^2+x+1\right)\)
\(=(x^4+x^2+1)-(x^3-1)\)
\(=[(x^4+x^3+x^2)-(x^3+x^2+x)+(x^2+x+1)]-(x-1)(x^2+x+1) \)
\(=[x^2(x^2+x+1)-x(x^2+x+1)+(x^2+x+1)]-(x-1)(x^2+x+1)\)
\(=(x^2-x+1)(x^2+x+1)-(x-1)(x^2+x+1)\)
\(=(x^2+x+1)(x^2-2x+2)\)