Question

Calcule,usando a regra dos produtos notáveis:

A)(x+y)²-2xy+(x+y).(x-y)=

B)(a+x)²+(a-x).(a+x)-2ax=

C)(a-1).(a+1)-(a+1)²-(a-1)²=

D)(x-2)²+(x+2).(x-2)=

Answer 1

Resposta:

a) (x + y) ^2 - 2xy + (x + y) * (x - y)

x^2 + 2xy + y^2 - 2xy + x^2 -y ^2

2x^2

b) (a + x)^2 + (a - x) * (a + x)  - 2ax

a^2 + 2ax + x^2 + a^2 - x^2 - 2ax

2a^2

c) (a - 1) * (a + 1) - (a+1)^2 - (a - 1)^2

a^2 - 1 - (2^2 + 2a + 1 ) - ( a^2 -2a + 1 )

a^2 -1 - a^2 - 2a - 2a - 1 - a^2 +2a - 1

-3 - a ^2

d) (x - 2) ^2 + (x + 2) * (x - 2)

(x - 2) * (x - 2 + x +2)

(x - 2) * 2x

2x * (x - 2)