> restart:
> P1:=1.3+2.4*x+2*x^2-0.5*x^3+4*x^4;
> evalf(subs(x=1.2,P1));
> P1*x^3;
> P1*x^0;
> P1*x^1;
> P2:=-2.5+3.5*x-1.2*x^2;
> P1+P2;
> P1-P2;

                                      2        3      4
               P1 := 1.3 + 2.4 x + 2 x  - 0.5 x  + 4 x


                               14.4904


                                 2        3      4   3
               (1.3 + 2.4 x + 2 x  - 0.5 x  + 4 x ) x


                                   2        3      4
                  1.3 + 2.4 x + 2 x  - 0.5 x  + 4 x


                                  2        3      4
                (1.3 + 2.4 x + 2 x  - 0.5 x  + 4 x ) x


                                               2
                     P2 := -2.5 + 3.5 x - 1.2 x


                                    2        3      4
                -1.2 + 5.9 x + 0.8 x  - 0.5 x  + 4 x


                                    2        3      4
                 3.8 - 1.1 x + 3.2 x  - 0.5 x  + 4 x

> 
