bonsoir

A =  ( 2 x + 4 ) ( 4 x + 7 ) + ( 2 x + 4 ) ( 6 x + 3  )

  = ( 2 x + 4 ) ( 4 x + 7 + 6 x + 3)

  = ( 2 x + 4 ) ( 10 x + 10  )

  = 10 ( 2 x + 4 ) ( x + 1 )

B =  ( 3 x - 7 )² + ( 3 x - 7 ) ( 2 x -  4 )

  = ( 3 x - 7 ) ( 3 x - 7 + 2 x - 4 )

  = ( 3 x - 7 ) ( 5 x - 11  )

c =  ( 2 x - 5 )² + 2 x  - 5

C =  ( 2 x - 5)  ( 2 x - 5 + 1  )

C =  ( 2 x - 5 ) ( 2 x - 4 )

   = 2 ( 2 x - 5 ) ( x - 2 )

D =  ( 7 x + 5 ) ( 7 x - 3 ) - ( 7 x + 5 ) ( 5 x + 2 )

  = ( 7 x + 5 ) ( 7 x - 3 - 5 x - 2 )

  = ( 7 x + 5) ( 2 x - 5)

E = ( 6 x + 2)² - ( 6 x + 2 ) ( 4 x - 4 )

  = ( 6 x + 2 ) ( 6 x + 2 - 4 x + 4 )

  = ( 6 x + 2 ) ( 2 x + 6 )

  = 4 ( 3 x + 1 ) ( x + 3)

f = ( x + 5 )²  - ( x + 5 )

 = ( x + 5 ) ( x + 5 - 1  )

 = ( x + 5 ) ( x + 4 )