bonsoir
( x + 5 )² - ( 2 x - 4 ) ²
= x² + 10 x + 25 - ( 4 x² - 16 x + 16 )
= x² + 10 x + 25 - 4 x² + 16 x - 16
= - 3 x² + 26 x + 9
( 3 x + 2 ) ( 2 x - 1 )²
= ( 3 x + 2 ) ( 4 x² - 4 x + 1 )
= 12 x ³ - 12 x² + 3 x + 8 x² - 8 x + 2
= 12 x ³ - 4 x² - 5 x + 2
