bonjour
( 4 x² - 9 ) - ( 2 x + 3 ) ( x + 1 )
= ( 2 x - 3 ) ( 2 x + 3 ) - ( 2 x + 3 ) ( x + 1 )
= ( 2 x + 3 ) ( 2 x - 3 - x - 1 )
= ( 2 x + 3 ) ( x - 4)
