bonjour
A = ( 2 x - 3 )² - ( 4 x + 7 ) ( 2 x - 3 )
1. A = 4 x² - 12 x + 9 - ( 8 x² - 12 x + 14 x - 21 )
A = 4 x² - 12 x - 8 x² + 12 x - 14 x + 21
A = - 4 x² - 14 x + 21
2. = ( 2 x - 3 ) ( 2 x - 3 - 4 x - 7 )
= ( 2 x - 3 ) ( - 2 x - 10 )
A = 0
x = 3/2 ou - 5
