Answer:

5x² + 12x + 12 = 0

Step-by-step explanation:

1/x² + 1/x + 1 = 7/12

(1+x+x²)/(x²) = 7/12

(1+x+x²) (12) = (7) (x²)

12 + 12x + 12x² = 7x²

12 + 12x + 12x² - 7x² = 0

12 + 12x + 5x² = 0  

5x² + 12x + 12 = 0