\(x^4-x^3-10x^2+2x+4\)
\(=x^2+2x^3-2x^2-3x^3-6x^2+6x-2x^2-4x+4\)
\(=\left(x^4+2x^3-2x^2\right)-\left(3x^3+6x^2-6x\right)-\left(2x^2+4x-4\right)\)
\(=x^2\left(x^2+2x-2\right)-3x\left(x^2+2x-2\right)-2\left(x^2+2x-2\right)\)
\(=\left(x^2+2x-2\right)\left(x^2-3x-2\right)\)