The teacher will be very surprised to see your correct solution 😉
a*x^2 + b*x + c = 0
D = b^2 - 4 * a * c =
(6)^2 - 4 * (1) * (7) = 8
x1 = (-b + sqrt(D)) / (2*a)
x2 = (-b - sqrt(D)) / (2*a)
___ x1 = -3 - \/ 2
___ x2 = -3 + \/ 2
x2 = -3 + sqrt(2)
sum
___ ___ -3 - \/ 2 + -3 + \/ 2
=
-6
product
/ ___\ / ___\ \-3 - \/ 2 /*\-3 + \/ 2 /
=
7
7