The teacher will be very surprised to see your correct solution 😉
4 3 2 x + x - 4*x + x + 1 = 0
x1 = 1
___ 3 \/ 5 x2 = - - - ----- 2 2
___ 3 \/ 5 x3 = - - + ----- 2 2
x3 = -3/2 + sqrt(5)/2
sum
___ ___ 3 \/ 5 3 \/ 5 1 + - - - ----- + - - + ----- 2 2 2 2
=
-2
product
/ ___\ / ___\ | 3 \/ 5 | | 3 \/ 5 | |- - - -----|*|- - + -----| \ 2 2 / \ 2 2 /
=
1
1
x1 = 1.0
x2 = -2.61803398874989
x3 = -0.381966011250105
x3 = -0.381966011250105