2*(2/x - x/3) = 2/x² + x²/18 +4/3
x≠0
умножаем лево право на 2
4*(2/x - x/3) = 4/x² + 2x²/18 +8/3
2*2/x*x/3=4/3
4*(2/x - x/3) = (2/x)² -2*2/x*x/3 + (x/3)² +4/3+8/3
4/3+8/3=12/3=4
4*(2/x - x/3) = (2/x -x/3)² +4
2/x-x/3=t
t²-4t+4=0
(t-2)²=0
t=2
2/x-x/3=2
6/3x - x²/3x - 6x/3x = 0
(6-x²-6x)/3x=0
x²+6x-6=0
D=36+24=60
x₁₂=(-6+-√60)/2= -3 +- √15
ответ -3 +- √15