bonsoir
A = 4 x² - 12 x + 9
= ( 2 x - 3 )²
B = ( 2 x - 3 ) ( 5 x - 7 - 2 x + 3 )
= ( 2 x - 3 ) ( 3 x - 4 )
B = 0
pour x = 3/2 ou 4 /3
pour x = - 1/2
B = ( - 2/2 - 3 ) ( - 3/2 - 4 )
= ( - 2/2 - 6/2 ) ( - 3/2 - 8/2 )
= - 8/2 x - 11 /2
= 88/4 = 22