Réponse:
Re bonjour
[tex]D= (2x-3)²-3(2x-3) \\ = 4x {}^{2} + 9 - 12x - 6x + 9 \\ = 4x {}^{2} - 18x + 18[/tex]
[tex]A= (x+2)(3x+1)-(x+2)(2x+3) \\ \\ = (3x {}^{2} + x + 6x + 2) - (2x {}^{2} + 3x + 4x + 6) \\ = 3x {}^{2} + x + 6x + 2 - 2x {}^{2} - 3x - 4x - 6 \\ = x {}^{2} - 4[/tex]
[tex]B= 9x²-25+(3x-5)(2x+15) \\ = 9x {}^{2} - 25 + 6x {}^{2} + 45 - 10x - 75 \\ = 15x {}^{2} - 10x - 55[/tex]
[tex]C= (x+2)(x-3)+(x-3) \\ = x {}^{2} - 3x + 2x - 6 + x - 3 \\ = x {}^{2} - 9 [/tex]
