Réponse :
bonjour
calcul et puis réduis
(8x-5)²=64x²-80x+25
(12x-7)(-2x+3)=-24x²+36x+14-21=-24x²+36x-7
(15x-11)(15x+11)=225x²-121
(9x+8)²=81x²+144x+64
(3x+2)(2x-3)+(4-3x)(4-3x)+(5x-2)²=6x²-9x+4x-6+16-12x-12x+9x²+25x²-20x+4=
6x²+9x²+25x²-9x+4x-12x-12x-20x-6+16+4=40x²-49x+14
(2x+6)²-(5x-3)(5x+9)+(2x-4)²=4x²+24x+36-25x²-45x+15x+27+4x²-16x+8=4x²-25x²+4x²+24x-45x+15x-16x+36+27+8=-17x²+10x+71
(4x-3)(-x-2)+(5x+2)²-(x-3)²=-4x²-8x+3x+6+25x²+20x+4-x²+6x-9=-4x²+25x²-x²-8x+3x+2x+6x+6+4-9=20x²+3x+1
(7x+2)²-(6x+7)+(2x-3)(-3x+2)=49x²+28x+4-6x-7-6x²+4x+9x-6=49x²-6x²+28x-6x+4x+9x+4-7-6=43x²+26x-9
(12-4x)(-x+3)+(x-2)²+(3x+4)²=-12x+36+4x²-12x+x²-4x+4+9x²+24x+16=
4x²+x²+9x²-12x-12x-4x+24x+4+16+36=14x²-4x+56
(15x+7)²=225x²+210x+49
Explications étape par étape :
