x² + 7x + 6 =
= (x + 3,5)² - 12,25 + 6 =
= (x + 3,5)² - 6,25 =
= (x + 3,5)² - 2,5² =
= (x + 3,5 + 2,5)(x + 3,5 - 2,5) =
= (x+6)(x+1)
b)
x² +11x +18 =
= (x+5,5)² - 30,25 + 18 =
= (x+5,5)² -12,25 =
= (x+5,5)² - (3,5)² =
= (x + 5,5 + 3,5)(x+5,5-3,5) =
= (x+9)(x+2)
Sper ca te ajuta!