bonsoir
A (x ) = ( 3 x - 5 )² - ( 3 x - 5 ) ( 8 x - 2 )
A (x) = 9 x² - 30 x + 25 - ( 24 x² - 6 x - 40 x + 10 )
A ( x ) = 9 x² - 30 x + 25 - 24 x² + 46 x - 10
A (x) = - 15 x² + 16 x + 15
A (x) = ( 3 x - 5 ) ( 3 x - 5 - 8 x + 2 )
A (x) = ( 3 x - 5 ) ( - 5 x - 3 )
f (7 ) = ( 21 - 5 ) ( - 35 - 3 ) = 16 * - 38 = - 608
f ( - 5/3 ) = - 15 ( - 5/3)² + 16 ( - 5/3) + 15
= - 15 ( 25/9 ) - 80/3 + 15
= - 375 /9 - 240/9 + 135/9
= - 480/ 9 = - 160/ 3
