2·x·(3·x - 1/3) - √7/3·(8·x - 1) - 7/6 = 0
(6·x^2 - 2·x/3) - (8·√7·x/3 - √7/3) - 7/6 = 0
6·x^2 - 2·x·(4·√7 + 1)/3 + √7/3 - 7/6 = 0
(6·x^2 - 2·x·(4·√7 + 1)/3 + √7/3 - 7/6 = 0)·6
36·x^2 - 4·x·(4·√7 + 1) + (2·√7 - 7) = 0
Δ/4= (- 2·(4·√7 + 1))^2 - 36·(2·√7 - 7) = 704 - 40·√7
√(Δ/4) = √(704 - 40·√7)= 10·√7 - 2
x1 = (2·(4·√7 + 1) - (10·√7 - 2))/36
x1 = - (√7 - 2)/18
x = (2·(4·√7 + 1) + (10·√7 - 2))/36
x2 = √7/2
Quindi soluzione:
x = - (√7 - 2)/18 ∨ x = √7/2