bonsoir
(x +1) (x + 2) (x + 3)
= ( x² + 2 x + x + 2 ) ( x + 3)
= ( x² + 3 x + 2) ( x + 3)
= x ³ + 3 x² + 3 x² + 9 x + 2 x + 6
= x ³ + 6 x² + 11 x + 6
( 3 - 2 x )² = 9 - 12 x + 4 x²
2 ( 4 x + 1) ( 2 x - 3)
= ( 8 x + 2) ( 2 x - 3)
= 16 x² - 24 x + 4 x - 6
= 16 x² - 20 x - 6