\(x^5-5x^3+4x\)
=\(x^5-x^3-4x^3+4x\)
=\(x^3\left(x^2-1\right)-4x\left(x^2-1\right)\)
=\(\left(x^3-4x\right)\left(x^2-1\right)\)
=\(x\left(x^2-4\right)\left(x-1\right)\left(x+1\right)\)
=\(x\left(x-2\right)\left(x+2\right)\left(x+1\right)\left(x-1\right)\)