bonsoir

F =  ( x + 3 ) ( x + 3 - 4 x + 1 )

  = ( x + 3 ) ( - 3 x + 4 )

G =  ( 5 - x ) ( 2 x + 3 - 6 + 5 x )

  = ( 5 - x ) ( 7 x - 3 )

H = ( 2x - 5 ) ( 4 x - 1 + 2 x - 5 )

   = ( 2 x - 5 ) ( 6 x - 6 )

   = 6 ( 2 x - 5 ) ( x - 1 )

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

  = ( 3 x + 5 ) ( x + 7 )

J = ( 4 - x ) ( 4 - x + 2 x + 1 + 3 x - 2 )

  = ( 4 - x ) ( 4 x + 3 )