Bonjour pouvez vous m aider svp conforme avec le programme de 3ème

• 5x + 3 = 8
• 3x – 7 = 11
• - 5x +7 = 1
• 10x–1=-5


Sagot :

Bonjour,

 • 5x + 3 = 8

⇔ 5x = 8 - 3

⇔ 5x = 5

⇔ x = 5/5

⇔ x = 1

  • 3x – 7 = 11

⇔ 3x = 11 + 7

⇔ 3x = 18

⇔ x = 18/3

⇔ x = 6

  • - 5x +7 = 1

⇔ - 5x = 1 - 7

⇔ - 5x = - 6

⇔ x = (-6)/(-5)

⇔ x = 6/5

  • 10x – 1 = - 5

⇔10x = - 5 + 1

⇔10x = - 4

⇔ x = -4/10

⇔ x = (-2 * 2)/(2 * 5 )

⇔ x = - 2/5