Question

Usando as rregras dos produtos notáveis , calcule :

a) (7a+1) (7a-1)

b) (2+9x)² 

c)(6x-y)² 

d)(3x +2 sobre3 a)² 

Answer 1

 

 

a) (7a+1) (7a-1)

 

49â^2 - 1

 

b) (2+9x)² = 4 + 36x + 81x^2

 

c)(6x-y)² = 36x^2 - 12xy + y^2

 

d)(3x +2 sobre3 a)² = ((3x + 2)/3)^2 = 9x^2 + 12x + 4 

                                                                9

Answer 2

a) $(7\text{a}+1)\cdot(7\text{a}-1)$

 

$=(7\text{a})^2-1^2=49\text{a}^2-1$

 

 

b) $(2+9\text{x})^2$

 

$=4+36\text{x}+81\text{x}^2$

 

 

c) $(6\text{x}-\text{y})^2$

 

$=36\text{x}^2-12\text{xy}+\text{y}^2$

 

 

d) $(3\text{x}+\frac{2}{3})^2$

 

$=9\text{x}^2+4\text{x}+\dfrac{4}{9}$