Question

Phân tích đa thức thành nhân tử

( 3x - 1 )² - ( x + 3 )²

Answer 1

\(\left(3x-1\right)^2-\left(x+3\right)^2\)

\(=\left(3x-1+x+3\right)\left(3x-1-x-3\right)\)

\(=\left(4x+2\right)\left(2x-4\right)\)

\(=4\left(2x+1\right)\left(x-2\right)\)

Answer 2

( 3x - 1 )² - ( x + 3 )² = ( 3x -1 - x - 3 ) ( 3x -1 + x + 3 )

= ( 2x - 4 ) ( 4x + 2)

= 2 ( x - 2 ) + 2 ( 2x + 1 )

= 4 ( x - 2 ) ( 2x + 1 )