Bonjours je n’arrive pas a faire ces équations pouvez vous m’aider svp ? Merci ! 1. -5x +2 = -3-7 2. 5(x-8) = -7(9x-4) +10 3. (2x-5) (-3x +7) = 0

Réponse :

Bonjour,

Explications :

1. -5x +2 = -3-7

<=> -5x+2 = -10

<=> -5x = -12

<=> x = -12/-5

<=> x = 12/5

2. 5(x-8) = -7(9x-4) +10

<=> 5x-40 = -63x+28+10

<=> 5x-40 = -63x+38

<=> 5x = -63x+78

<=> 68x = 78

<=> x = 78/68

<=> x = 39/34

3. (2x-5) (-3x +7) = 0

<=> 2x-5 = 0 ou -3x+7 = 0

<=> 2x = 5 ou -3x = -7

<=> x = 5/2 ou x = -7/-3

<=> x = 5/2 ou x = 7/3

Voilà, bonne journée :)

Bonjour,

1. -5x +2 = -3-7

- 5x = - 3 - 7 - 2

- 5x = - 12

x = 12/5

2. 5(x-8) = -7(9x-4) +10

5x - 40 = - 63x + 28 + 10

5x + 63x = 28 + 10 + 40

68x = 78

x = 78/68

x = 39/34

3. (2x-5) (-3x +7) = 0

2x - 5 = 0       ou       - 3x + 7 = 0

2x = 5                        - 3x = - 7

x = 5/2                        x = 7/3.