(9c^2+c^6)(9c^2-c^6)= i 9 %

This is a difference of squares: (a + b)(a - b) = a² - b².<br /><br />Therefore, (9c² + c⁶)(9c² - c⁶) = (9c²)² - (c⁶)² = 81c⁴ - c¹²<br />