x^4-4x^3+6x^2-4x+3=x^4-2x^3-2x^3+6x^2-4x+3=x^2(x^2-2x)-2x^3+4x^2+2x^2-4x+3=-2x^3+4x^2+4x^2-4x+3=-2x(x^2-2x)+4x^2-4x+3=-4x+4x^2-4x+3=4x^2-8x+3=4(x^2-2x)+3=4*2+3=11