Verified answer

Ответ:

[tex]10[/tex]

Объяснение:

[tex]3x+\frac{1}{x}=-4\ \ \ |()^2\\\\9x^2+2\cdot 3x\cdot \frac{1}{x}+\frac{1}{x^2}=16\\\\9x^2+6+\frac{1}{x^2}=16\\\\9x^2+\frac{1}{x^2}=16-6\\\\9x^2+\frac{1}{x^2}=10[/tex]