The teacher will be very surprised to see your correct solution 😉
a*x^2 + b*x + c = 0
D = b^2 - 4 * a * c =
(2)^2 - 4 * (1) * (-2) = 12
x1 = (-b + sqrt(D)) / (2*a)
x2 = (-b - sqrt(D)) / (2*a)
___ x1 = -1 + \/ 3
___ x2 = -1 - \/ 3
x2 = -sqrt(3) - 1
sum
___ ___ -1 + \/ 3 + -1 - \/ 3
=
-2
product
/ ___\ / ___\ \-1 + \/ 3 /*\-1 - \/ 3 /
=
-2
-2