Resposta :
(x²)² + 2.x².9 + 9² - 36x²
= (x²)² + 18x² + 81 - 36x²
= (x²)² - 18x² +81
= (x² - 9)²
= [(x-3) . (x+3)]²
= (x-3)² . (x+3)²
= (x²)² + 18x² + 81 - 36x²
= (x²)² - 18x² +81
= (x² - 9)²
= [(x-3) . (x+3)]²
= (x-3)² . (x+3)²