Bonjour,

Exercice 2

-/ 5x - 21 = 30

  5x = 30 + 21

  5x = 51

  x = 51/5

-/ je ne sais pas

-/ -3x - 7 = x + 3

  -3x + x = 3 + 7

  -4x = 10

   x = 10/-4

-/ -3x + 8 = 5

  -3x = 5 - 8

  -3x = -3

   x = -3/-3

les 2 dernières, je n'ai pas encore appris à les résoudre

☺ Bonne après midi ☺

Bonjour,

-3x +8 = 5

-3x = 5-8 =-3

x = -3/-3 = 1

2x/3 + 1/8 =9

2x/3 = 9-1/8

2x/3 = 72/ 8 -1/8 = 71/8

2x = 71/8 * 3= 213/8

x = (213/8 )/2 = 213 / (8*2) = 213/ 16

2(3x+5) = x+5

6x+10 =x+5

6x-x = 5 -10

5x = -5

x= -55 =-1

5x-21 =30

5x= 30+21 =51

x= 51/5

3x +5/3 =7/9

3x = 7/9 - 5/3

3x= 7/9 - 15/9 = -8/9

x = (-8/9 )/3

x = -8/(9*3) = -8 /27

-3x -7 =-x +3

-3x+x =3 +7

-2x = 10

x = 10/-2 = -5