Réponse :

bonjour

f (x) = - 3 x + 7

f (8) = - 24 + 7 = - 17

f (0) = 7

- 3 x + 7 = 2

- 3 x = 2 - 7 = - 5

x = 5/3

- 3 x + 7 = 10

- 3 x = 10-  7 = 3

x = - 1

- 3 x + 7 = 0

- 3 x = -  7

x = 7/3

- 3 x + 7 = 8

- 3 x = 8 - 7

- 3 x = 1

x = - 1/3

- 3 x + 7 = 16

- 3 x = 16 - 7

- 3 x = 9

x = - 9/3 = - 3

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