Réponse :
bonsoir
f (x) = 3 x - 6
f (0) = - 6
f ( 1/3) = 3/3 - 6 = 1 - 6 = - 5
f ( 8/6) = 24/6 - 6 = 4 - 6 = - 2
3 x - 6 = 0
3 x = 6
x = 2
antécédent = 2
f (x) > 0
f (x) > 2
[ 2 ; + ∞ [
f (x) = 4 x - 10 et g (x) = 10 x + 5
f (0) = - 10
f ( 11/4 ) = 44/4 - 10 = 11 - 10 = 1
g ( 3/5 ) = 30/5 + 5 = 6 + 5 = 11
4 x - 10 = 0
4 x = 10
x = 10/4 = 5/2
10 x + 5 = 0
10 x = - 5
x = - 5/10 = - 1/2
4 x - 10 ≥ 10 x + 5
4 x - 10 x ≥ 5 + 10
- 6 x ≥ 15
x ≤ - 15/6
] - ∞ : - 15/6 ]
Explications étape par étape :
