Bonjour

A = (3x - 2) (5x + 4)

A = 15x² + 12x - 10x - 8

A = 15x² + 2x - 8

B = (3 - x) (4x - 1)

B = 12x - 3 - 4x² + x

B = - 4x² + 12x + x - 3

B = - 4x² + 13x - 3

C = 3 - x (4x - 1)

C = 3 - 4x² + x

C = - 4x² + x + 3

D = (4x - 1)² + 8 (5x - 3)

D = 16x² - 8x + 1 + 40x - 24

D = 16x² - 8x + 40x + 1 - 24

D = 16x² + 32x - 23

E = (6x - 1) (2x + 3) - (5x - 4) (2x - 3)

E = 12x² + 18x - 2x - 3 - (10x² - 15x - 8x + 12)

E = 12x² + 18x - 2x - 3 - 10x² + 15x + 8x - 12

E = 12x² - 10x² + 18x + 15x + 8 x - 2x - 3 - 12

E = 2x² + 39x - 15.