bonjour
A = - 3 + 2 x
C = - 10 x² - 14 x
D = 8 x² - 24 x - 4 + 3 x = 8 x² - 21 x - 4
D = ( 2 x - 2 x² ) - ( 3 x² + 2 x - 9x - 6 )
= ( - 2 x² + 2 x ) - ( - 3 x² - 7 x - 6 )
= - 2 x² + 2 x + 3 x² + 7 x + 6
= x² + 9 x + 6
C = 2 ( x + 3 ) + ( 4 x² - 9 )
= 2 x + 6 + 4 x² - 9 = 4 x² + 2 x - 3
A = - 4 x + 8 = 6 x + 3 - x
- 4 x - 6 x + x = 3 - 8
- 9 x = - 5
x = 5 /6
B équation produit nul , x = - 7/3 ou 8/4 = 2
C = 4 x² + 4 x = - 1
4 x² + 4 x + 1 = 0
( 2 x + 1 ) ² = 0
x = - 1 /2