3x + 1 = -7x + 8 2x - 1 = 9x 4x + 5 = 8x + 2 aidez-moi svp (résoudre)

Hello !

3x + 1 = -7x + 8

3x + 7x = 8 - 1

10x = 7

x = 7/10

2x - 1 = 9x

2x - 9x = 1

-7x = 1

x = 1/-7

4x + 5 = 8x + 2

4x - 8x = 2 - 5

-4x = -3

x = -3/-4 = 3/4

les x à gauche et les constantes à droite - ce qui donne :

3x + 1 = -7x + 8

3x + 7x = 8 - 1

10x = 7

x = 7/10

2x - 1 = 9x

2x - 9x = 1

-7x = 1

x = -1/7

4x + 5 = 8x + 2

4x - 8x = 2 - 5

-4x = - 3

x = 3/4