Chapitre 9

Opérations sur les entiers

Activité 5 - Sommes et produits

a) Exprime l'aire de la surface non grisée de plusieurs manières.

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b) Réduis les sommes suivantes.

7a – 5a =
..........
– 2b + 8b =
..........
– 3a + a =
..........
5ab – 2ab =
..........
– 3a + 2a =
..........
– 3a – a =
..........
3a – 7a =
..........
– 2b – 5b =
..........
2b – 2b =
..........
2ab – 5ab =
..........
– 5b – 3b =
..........
– 5b – 2b =
..........
3x– 4x =
.........
2x + x =
.........
– 2b + 5b =
.........

c) Réduis les sommes suivantes, si cela est possible.

3a2 + 5a2 =
..........
4a – 5a =
..........
2b – b2 =
..........
5a2 – 3a2 =
..........
– 2a2 – 5a2 =
..........
b2 – 3b2 =
..........
6a2 – a2 =
..........
3a + 5a2 =
..........
– 3b + 2b =
..........
3a2 – 5a2 =
..........
– 4a + 3a2 =
..........
– b – b =
..........
– 2a2 – 3a2 =
.........
– 4a + 3a =
.........
– b2 – b2 =
.........

d)

Réduis les produits suivants.


a . b =
..........
(– 2) . a =
..........
2a . b =
..........
(– a) . b =
..........
(– 2) . (– b) =
..........
2a . (– 3b) =
..........
(– a) . (– b) =
..........
(– a) . (+2) =
..........
– a . (– 2b) =
..........
a . (– b) =
..........
– a . 5 =
..........
– 4a . 2b =
..........
4 . 2b =
.........
(– a) . (– 3) =
.........
– 2a . 2b =
.........
e) Réduis les produits suivants.

3a . 2a =
..........
– a . (– 3a) =
..........
3a . 2a . 5a =
..........
– 2b . 3b =
..........
a . (– 2c) =
..........
2a . (– 3a) . a =
..........
– 4c . (– 2c) =
..........
– 4a . (– 2b) =
..........
a . (– 2b) . (– 3c) =
..........
3a . (– 2b) =
..........
– 2a . (– a) =
..........
2a . (– 2a) . c =
..........
– a . (– 2b) =
.........
– 4x . 4x =
.........
– 4a . (– 2a) . (– 3a) =
.........

f)

Calcule la valeur numérique des expressions suivantes si tu sais que :


2a + 3a =
..........
2a . (– 3b) =
..........
2a . 7a . 5a =
..........
5a . 3a =
..........
3b – 2c =
..........
2a + 3a + 5a =
..........
4a – 6a =
..........
– a + 3a =
..........
– 4b . (– 2b) . b =
..........
– 2a – a =
..........
3a . (– a) =
..........
– 3b + 2b – 5b =
..........
– 2a . a =
.........
3b . (– 2c) =
.........
(– 3b) . (– 2b) . (– 5b) =
.........

Vos remarques sont les bienvenues.