Решите уравнение. 2*(x^2 + 1/ + 1/x)=6

Замена: x+1/x = t
(x+1/x)^2 = x^2+2+1/x^2 = t^2
получим:
2*(t^2 - 2) - t = 6
2t^2 - t - 10 = 0
D = 1+4*2*10 = 9^2
(t)1;2 = (1+-9)/4
x+1/x = 2.5                   x+1/x = -2
x^2 - 2.5x + 1 = 0          x^2 + 2x + 1 = 0
2x^2 - 5x + 2 = 0           (x+1)^2 = 0
D=25-4*2*2 = 3^2           x = -1
(x)1;2 = (5+-3)/4
x = 2
x = 0.5