bonjour
A (x) = ( 2 x - 3 ) ( 3 x + 2 ) - ( 3 - 2 x ) ( x + 1 )
A (x) = 6 x² + 4 x - 9 x - 6 - ( 3 x + 3 - 2 x² - 2 x )
A (x) = 6 x² - 5 x - 6 - 3 x - 3 + 2 x² + 2 x
A (x) = 8 x² - 6 x - 9
A (x) = ( 2 x - 3 ) ( 3 x + 2 ) - ( 3 - 2 x ) ( x + 1 )
A (x) = ( 2 x - 3 ) ( 3 x + 2 ) + ( - 3 + 2 x ) ( x + 1 )
A ( x ) = ( 2 x - 3 ) ( 3 x + 2 + x + 1 )
A ( x) = ( 2 x - 3 ) ( 4 x + 3 )
A (x) = 0
( 2 x - 3 ) ( 4 x + 3 ) = 0
soit 2 x - 3 = 0 et x = 3/2
soit 4 x + 3 = 0 et x = - 3/4
S ( - 3/4 ; 3/2 )