Developement & factorisations

1.sans poser d'operations

Completer:

13x22=13x(20+___ ) =13x20+13x ____ =____ + _____ = _____

Sur ce modele, calculer les produits suivants :

13 x 35 = 13 x (30+ ____ ) = ___________________________________

24 x 102=24 x (100+ _____ )= ___________________________________

2.Mise en facteur

Completer:

2 x 734 + 8 x 734 = ( _____ + _____ ) x 734 = ____ x 734 = ______________

Sur ce modèle, calculer:

57 x 25 + 43 x 25 = ___________________________________

113 x 28 - 13 x 28 = ____________________________________

4.Reduire les Expressions

11a - 8a + 5a - 2a = _________________________

15a - 3 + 7a + 4 - 8a = _____________________________

6a - (8a - 2 ) + (4a - 3 ) = _______________________________

5.Factoriser les expressions

7 x 2 + 7m = ______________________________________

7,2 x 5 - 5 n = ______________________________________

2,3 a + 2,3 b - 2,3 c = _________________________________

Merci de m'aider!

1

Réponses

2013-03-10T16:40:36+01:00

13 x 35 = 13 x (30 +5) = 13 x 30 + 13 x 5 = 390 + 65 = 455

24 x 102 = 24 x (100 +2) = 24 x 100 + 24 x 2 = 2400 +48 = 2 448

 

 

2) 57 x 25 +43 x 25 = (57 +43) x 25 = 100 x 25 = 2500

113 x 28 -13 x 28 = (113 -13) x 28 = 100 x 28 = 2800

 

4) 11a -8a+5a-2a = 16a -10a = 6a

      15a-3+7a+4-8a = 22a-8a+4 = 14a+4

     6a-(8a-2) +(4a-3)

 = 6a-8a+2+4a-3 = 2a-1

 

5) 7 x 2+7m = 14 + 7m = 7(2 +m)

7.2 x 5 -5n = es tu sûre du 7.2 ?

2.3a +2.3b-2.3c = 2.3(a+b-c)