DM_no4-Corrige-5.doc
DM n°4 (« force 2 ») ? 2nde5 ? 2012/2013. Correction. Exercice 1. A = 2(x+3)(3x-
7)-(x-6)(-3x+4). = (2x+6)(3x-7)-(-3x²+4x+18x-24). = 6x²-14x+18x-42+3x²-4x-18x+
24. = 9x²-18x-18. B = (2x+1)²(x-2)-5x(x-3)². = (4x²+4x+1)(x-2)-5x(x²-6x+9). = 4x3-
8x²+4x²-8x+x-2-5x3+30x²-45x. = -x3+26x²-52x-2. C = (5x+3)²-(2x+3)(2x-3)+(4-6x)
².