2x^5＋3x^3＋5x^2－2x+10
=2x^5+2x^3＋x^3＋x+5x^2+5－3x+5
=2x^3(x^2+1)+x(x^2+1)+5(x^2+1)－3x+5
=(x^2+1)（2x^3+x+5)－3x+5
商2x^3+x+5
余－3x+5