The teacher will be very surprised to see your correct solution 😉
a*x^2 + b*x + c = 0
D = b^2 - 4 * a * c =
(-10)^2 - 4 * (3) * (5) = 40
x1 = (-b + sqrt(D)) / (2*a)
x2 = (-b - sqrt(D)) / (2*a)
sum
____ ____ 5 \/ 10 5 \/ 10 - - ------ + - + ------ 3 3 3 3
=
10/3
product
/ ____\ / ____\ |5 \/ 10 | |5 \/ 10 | |- - ------|*|- + ------| \3 3 / \3 3 /
=
5/3
5/3
____
5 \/ 10
x1 = - - ------
3 3
____
5 \/ 10
x2 = - + ------
3 3
x2 = sqrt(10)/3 + 5/3