Bonjour
A = ( 4 x + 2) ( 4 x - 2 ) + ( 5 x + 3 ) ( 4 x + 2 )
1 ) A = 16 x² - 4 + 20 x² + 10 x + 12 x + 6
= 36 x² + 22 x + 2
2) si x = 3
36 ( 3)² + 22 * 3 + 2
= 324 + 66 + 2
= 392
si x = - 4
36 ( - 4 )² + 22 ( - 4 ) + 2
36 *16 - 88 + 2
= 576 - 88 + 2
= 490
B = ( 9 x + 1 ) ( 4 x + 2 )
= 36 x² + 18 x + 4 x + 2
= 36 x² + 22 x + 2
A = B