Bonjour j'aimerait l'aide svp A=3(x-1)(x+1)+(2x+5)(x+1), B=4(3x+2)(5x+1)-2(3x-2)au carré, C=-(x-3)(x+3)-4(2x+1)(x+3)

Bonjour,

Développer les expressions:

A=3(x-1)(x+1)+(2x+5)(x+1)

A= 3(x²-1)+2x²+5x+2x+5

A= 3x²-3+2x²+7x+5

A= 5x²+7x+2

B=4(3x+2)(5x+1)-2(3x-2)²

B= 4(15x²+10x+3x+2)-2(9x²-12x+4)

B= 4(15x²+13x+2)-18x²+24x-8

A=  42x²+76x

C=-(x-3)(x+3)-4(2x+1)(x+3)

tu développes en faisant attention aux signes

Bonjour

A=3(x-1)(x+1)+(2x+5)(x+1)

3(x^2-1) + 2x^2 + 2x +5x +5

3x^2 -3+ 2x^2 + 7x + 5

5x^2 .+7x + 2

, B=4(3x+2)(5x+1)-2(3x-2)au carré

4(15x^2 + 3x + 10x + 2) -2(9x^2 -12x+4)

60x^2 + 12x + 40x + 8 -18x^2 +24x-8

42x^2 + 76x

C=-(x-3)(x+3)-4(2x+1)(x+3)

-(x^2-9) -4(2x^2 + 6x +x+3)

-x^2 + 9 -8x^2 -24x -4x -12

-9x^2 -28x -3