Sagot :
bonjour
1 ) 5 x - 15 - 3 x + 7 = 2 x - 8
2 ) 5 x - 15 - 3 x + 7 = 9
2 x - 8 = 9
2 x = 9 + 8
2 x = 17
x = 17/2
1 ) 2 x - 14
- 3 x + 3
2 x - 14 = - 3 x + 3
2 x + 3x = 3 + 14
5 x = 17
x = 17/5
42 - 14 x - 12 x - 3 = 0
- 26 x = - 42 + 3
- 26 x = - 39
x = 39/26 = 3/2
Réponse:
Exercice 3:
1) 5(x-3) -3x +7 = 5x-15-3x+7= 2x - 8
2) 2x-8 = 9 , 2x-8-9= 0 soit 2x-17=0 , x= 17/2
Exercice 4:
1) 2(x-7)= 2x -14 et 3(-x+1) = -3x +3
2)
2x-14 = -3x +3
5x = 17
x= 17/5
Exercice 5:
1)
7(6-2x) - 3 (4x+1) = 0
(42 - 14x) - ( 12x +3) = 0
42 -14x -12x -3 =0
-26x + 39 = 0
-26x= -39
x= 39/26
x= 1.5