Question

1.Desenvolva os produtos :

a.(2x+3)²
b.(2a² - 3)³

Answer 1

a) (2x + 3)² = 4x² +12x + 9
b) (2a² - 3)³ = (2a²)³ - 3.4a^4 . 3 + 3.2a².9 -3³ = 8a^6 - 36a^4 + 54a² - 27

Answer 2

a.
= (2x + 3)²
= (2x)² + 2.3.2x + 3²
= 4x² + 12x + 9
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨
b.
= (2a² - 3)³

= (2a² - 3)².(2a² - 3)

= [(2a²)² - 2.3.2a² + 9)] . (2a² - 3)

= [4a⁴ - 12a² + 9]. (2a² - 3)

= 4a⁴.2a² + 4a⁴.(-3) - 12a².2a² - 12a².(-3) + 9.2a² + 9.(-3)

= 8a⁶ - 12a⁴ - 24a⁴ + 36a² + 18a² - 27

= 8a⁶ - 36a⁴ + 54a² - 27