The teacher will be very surprised to see your correct solution 😉
2 1 6*x - 6*x - 36*x - 40 = 0
a*x^2 + b*x + c = 0
D = b^2 - 4 * a * c =
(-42)^2 - 4 * (6) * (-40) = 2724
x1 = (-b + sqrt(D)) / (2*a)
x2 = (-b - sqrt(D)) / (2*a)
sum
_____ _____ 7 \/ 681 7 \/ 681 - - ------- + - + ------- 2 6 2 6
=
7
product
/ _____\ / _____\ |7 \/ 681 | |7 \/ 681 | |- - -------|*|- + -------| \2 6 / \2 6 /
=
-20/3
-20/3
_____
7 \/ 681
x1 = - - -------
2 6
_____
7 \/ 681
x2 = - + -------
2 6
x2 = 7/2 + sqrt(681)/6