bonjour
f (x) = - 4 x + 7
f (2) = - 8 + 7 = - 1
f ( - 3 ) = 12 + 7 = 19
f (0) = 7
f ( - 5/2) = 20/2 + 7 = 17
- 4 x + 7 = 15
- 4 x = 15 - 7
- 4 x = 8
x = - 2
