Bonsoir
A= 3x(5 - 4x) - 3 - 4x(7x - 3)
A = 15x - 12x² - 3 - 28x² + 12x
A = - 12x² - 28x² + 15x + 12x - 3
A = - 40x² + 27x - 3
B = 2x(5x - 2) + 4x - 2x(7x + 1)
B = 10x² - 4x + 4x - 14x² - 2x
B = 10x² - 14x² - 4x + 4x - 2x
B = - 4x² - 2x
C = 6 - 2x[7-2(3x + 1)] + 2(5 - 3x)
C = 6 - 2x (7 - 6x - 2) + 10 - 6x
C = 6 - 14x + 12x² + 4x + 10 - 6x
C = 12x² - 14x - 6x + 4x + 6 + 10
C = 12x² - 16x + 16
D = x - x[3-(7 - x)]- 2x - (4x -(x-2)]
D = x - x (3 - 7 + x) - 2x - (4x - x + 2)
D = x - 3x + 7x - x² - 2x - 4x + x - 2
D = - x² - 3x - 2x - 4x - x + x + 7x - 2
D = - x² - 2.
Bonsoir,
Développer:
A= 3x(5 - 4x) - 3 - 4x(7x - 3)= 15x-12x²-3-28x²+12x= -40x²+27x-3
B = 2x(5x - 2) + 4x - 2x(7x + 1)= 10x²-4x+4x-14x²-2x= -4x²-2x
C = 6 - 2x[7-2(3x + 1)] + 2(5 - 3x)= 6-2x(7-6x-2)+10-6x= 16-2x(-6x+5)-6x
= 16+12x²-10x-6x= 12x²-16x+16
D = x - x[3-(7 - x)]- 2x - (4x -(x-2))= x-x[3-7+x ]-2x-(4x-x+2)= x-x(x-4)-2x-3x-2
= x-x²+4x-5x-2= -x²-2