According to Vieta's theorem.

x 1+x2=2

x 1*x2=a

X 1+x2=3- radical number 2 (21/2)

Three unknowns, three equations, get

x 1= 1+2^ 1/2,x2= 1-2^ 1/2,a=- 1.

(2)

x 1^3-3x 1^2+2x 1+x2

=x 1^3-x 1^2-(2x 1^2-2x 1)+x2

=x 1^2(x 1- 1)-2x 1(x 1- 1)+x2

=(x 1- 1)(x 1^2-2x 1)+x2

=(x 1- 1)[(x 1- 1)^2- 1]+x2

Then substitute the values of x 1 and x2 in the first question to get 1.