Réponse :
bonjour,
A = ( 2x - 3 ) ²
= (2x) ² - 2×2x×3 + 3²
= 4x²-12x + 9
B = 2x( x+1 ) - 5 ( x-3)
=2x²+2x - ( 5x -15 )
= 2x² +2x - 5x +15
= 2x²- 3x +15
f(x) = 1/3 x +5
fx) = 2
1/3 x +5 = 2
1/3 x = 2 -5
1/3 x = -3
1/3 x × 3 = -3×3
1x = -9
x = -9
l'antecedent de 2 par la fonction f est -9
3x - 8 = 0
3x = 8
x = 8/3
4t +1 = 9t -6
4t - 9t = -6 -1
-5t = -7
t = -7/-5
t = 7/5
(5x - 8 ) ( 5 - x ) = 0
5x - 8 = 0 ou 5 -x = 0
5x = 8 -x = -5
x = 8/5 x = 5
pour les inequations il faut faire des tableaux de signes
voila:)
