Bonjour pouvez-vous m’aider svp. Merci d’avance <3 - 4ème

Bonjour

1)

28x - 5 = 10x + 3

28x - 10x = 3 + 5

18x = 8

x = 8/18

x = 4/9

2)

7 (x + 5) = 8x - 3

7x + 35 = 8x - 3

7x - 8x = - 3 - 35

- x = - 38

x = 38

3)

1/4 (x + 7) = 3/2 (x - 7)

1/4x + 7/4 = 3/2x - 21/2

1/4x - 3/2x = - 21/2 - 7/4

1/4x - 6/4x = - 42/4 - 7/4

- 5/4x = - 49/4.

- 5x = - 49

x = 49/5

4)

2/3 (x - 7) = 1/3 (2x + 10)

2/3x - 14/3 = 2/3x + 10/3

2/3x - 2/3x = 10/3 + 14/3

0x = 24/3 → Impossible

5)

x (x + 1) = 0

x = 0            ou            x + 1 = 0

                                     x = - 1