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
