Question

Dados A= ( 2x - 1 ) e B= ( 2x + 1 ), calcule: 
a) A² - B² =

b) (A - B )² =

Answer 1

Dados A= ( 2x - 1 ) e B= ( 2x + 1 ), calcule: 



a)( 2x - 1 )² - ( 2x + 1 )² =

4x² - 4x + 1 - ( 4x² + 4x + 1)
4x² - 4x + 1 - 4x² - 4x - 1

- 8x 

b) ( 2x - 1  - 2x - 1 )² = (- 2 )²  ==> 4

Answer 2

A) (2x-1).(2x-1) = 4x²-2x-2x+1
A² = 4x²-4x+1
(2x+1).(2x+1)=
4x²+2x+2x+1
B²= 4x²+4x+1

A²-b²= 4x²-4x+1 - 4x²+4x+1=  [2]

B)(2x-1 - 2x+1)² = 
0²= [0]