Réponses

2014-03-03T22:23:29+01:00
((x-2)-(2x+5))((x-2)+(2x+5)
((3-x)-(3x+2))((3-x)+(3x+2))
((-x+4)-(6x-1))((-x+4)+(6x-1))
((3x+2)-(2x+7))((3x+2)+(2x+7))
2014-03-03T22:23:40+01:00
(x-2)²-(2x+5)² = [ (x-2) -( 2x+5) ] [(x -2 ) + (2x +5) ]
                      = [ x-2 - 2x -5 ] [ x - 2 +2x +5 ]
                      = ( - x -7 ) ( 3x +3 )
                  ou    = ( -x -7) 3(x+1)

        A² -B² = ( A-B) (A + B)

tu continues avec les autres exercices et tu réduis , bon courage