bonjour

x = - 2

2 x   = - 4

7 + 5 x =   7 + 5 *-2 = 7 - 10 = - 3

4 x - 8 = 3 x + 6

4 x - 3 x = 6 + 8

x = 14

14 est solution

aire  = 5 ( x + 2 ) = 5 x + 10

P = 2 ( 5 + x + 2 ) = 10 + 2 x + 4 = 2 x + 14

Réponse:

exercice 1

a) 2x ou x=-2 alors 2×-2 = -4

b) 7+ 5×(-2) = 7-10 = -3

exercice 2

vérifions cela

4(x-2) = 3x+6

4x-8 = 3x +6

4x -3x = 8+6

x= 14

4(22-2) = 3×22 +6

88-8 = 66+6

j ai pas réussi pour le 22...

exercice 3

A= 5(x+2) = 5×x +5×2 = 5x +10

P ou perimetre = 2(5+x+2) = 2×5 +2×x +2×2 = 10 +2x +4 = 14 +2x soit 2x+14