Bonjour,
1) (2x+2)²-9 utiliser (a+b)² = a²+2ab+b²
4x²+8x+4-9
4x²+8x-5
2) 9x²-4+(3x-2)(x-3)
9x²-4+3x²-9x-2x+6
12x²+2-11x
12x²-11x+2
3) (2x+4)²-20 utiliser (a+b)² = a²+2ab+b²
4x²+16x+16-20
4x²+16x-4
4) (2x+7)(2x-3)
2x×2x-2x×3+7×2x-7×3
4x²-6x+14x-21
4x²+8x-21
5) (x+2)(3x+1)-(x+2)(2x+3)
(x+2)(3x+1-(2x+3))
(x+2)(3x+1-2x-3)
(x+2)(x-2) utiliser (a+b)(a-b) = a²-b²
x²-4
6) (3x+1)²-4 utiliser (a+b)² = a²+2ab+b²
9x²+6x+1-4
9x²+6x-3
7) (2x-3)²-3(2x-3) utiliser (a-b)² = a²-2ab+b²
4x²-12x+9-3(2x-3)
4x²-12x+9-6x+9
4x²-18x+18
8) (x+2)(x-3)+(x-3)
(x-3)(x+2+1)
(x-3)(x+3) utiliser (a-b)(a+b) = a²-b²
x²-9
9) (3x-7)²-29 utiliser (a-b)² = a²-2ab+b²
9x²-42x+49-29
9x²-42x+20
10) 9x²-25+(3x-5)(2x+15)
9x²-25+6x²+45x-10x-75
15x²-100+35x
15x²+35x-100
