bonjour
A(x)=(2x-3)(x² -1)
A (x) = 2 x ³ - 2 x - 3 x² + 3
B(x)=(2-3x)(x-4)-(4-7x)(6+3x)
B (x) = 2 x² - 8 - 3 x² + 12 x - ( 24 + 12 x - 42 x - 21 x² )
B (x) = - x² + 12 x - 8 + 21 x² - 12 x + 42 x - 24
B (x) = - x² + 12 x - 8 + 21 x² + 30 x - 24
B (x) = 20 x² + 42 x - 32