x+1*x^2+1

x+1*x^2+1

$$x+1*x^2+1=x+x^2+1=x^2+x+1$$

perhaps you really mean

(x+1)*(x^2+1)

$$\\(x+1)*(x^2+1)\\
=x(x^2+1)+1(x^2+1)\\
=x^3+x+x^2+1\\
=x^3+x^2+x+1$$