bonjour
1 ) h (x) = - 5 x
h ( 5) = - 25
- 5 x = - 3
x = 3/5
antécédent de - 3 = 3/5
b ) i ( 5) = 2
i (x) = 2 x / 5
2 ) f (x) = 3 x - 5
f ( 5) = 15 - 5 = 10
f ( - 2 ) = - 6 - 5 = - 11
3 x - 5 = 7
3 x = 7 + 5
3 x = 12
x = 4
f (4) = 7
3 x - 5 = - 2 x
3 x + 2 x = 5
5 x = 5
x = 1
même image pour x = 1