b: \(=2x^4-6x^3+4x^3-12x^2+3x^2-9x+6x-18\)
\(=\left(x-3\right)\left(2x^3+4x^2+3x+6\right)\)
\(=\left(x-3\right)\left(x+2\right)\left(2x^2+3\right)\)
c: \(x^5-2x^4+2x^3-4x^2-3x+6\)
\(=\left(x-2\right)\left(x^4+2x^2-3\right)\)
\(=\left(x-2\right)\left(x^2+3\right)\left(x^2-1\right)\)
\(=\left(x-2\right)\left(x-1\right)\left(x+1\right)\left(x^2+3\right)\)