Développe et réduis ces expressions. A= 2x(x-3) B=(5x+2)x 4x C=(x+1)(4-x) D=(x-2)(3x-1)

A = 2x(x-3)
A= 2x² - 6x

B = (5x+2)*4x
B = 20x² + 8x

C = (x+1)(4-x)
C = 4x + 4 - x² - x
C = -x² + 3x + 4

D = (x-2)(3x-1)
D = 3x² - 6x - x + 2
D = 3x² - 7x + 2