Question

calcule:
a) ( 3ab - 1)²
b) (x+y)²

Answer 1

Resposta:

a)

(3ab - 1)²

= (3ab)² + 2 . 3ab . - 1 + 1²  

= 9a²b² - 6ab + 1      

b)

(x + y)² = x² + 2.x.y + y² = x² + 2xy + y²