Developper et réduire: A=6x-3(x+1)² B=-3x(x-4)² C=(-x-7)(3-5x)

Bonjour,

A = 6x - 3(x + 1)²
A = 6x - 3(x² + 2x + 1)
A = 6x - 3x² - 6x - 3
A = -3x² - 3

B = -3x(x - 4)²
B = -3x(x² - 8x + 16)
B = -3x^3 + 24x² - 48x


C = (-x - 7)(3 - 5x)
C = -3x + 5x² - 21 + 35x
C = 5x² + 32x - 21

A=6x-3(x+1)²
=6x-3(x²+2x+1)
=6x-3x²-6x+3
=3x²+3

B=-3x(x-4)²
=-3x(x²-16)
=-3x³+48x²


C=(-x-7)(3-5x)
=5x²+32x-21