Exercice 1: Développer les expressions suivantes : A = (x - 1)(x + 2) = 2² +² - 20 - 2 = 7c²+x=2 B = (x-3)(x + 5) = 2c²+ Sac - 32c-15= x² + 20+ Y5 C = (x-6) (2x - 3) = 20c²-3x - 122 +18 = 2x² - 15 oct 18 D=(5-4x) -3- (7x-3) = E = (5x-2) + 4x - (7x + 1) F = 3-[7-(3x + 1)] + (5 - 3x) G = 4x + [3-(7-x)]- [4x - (x - 2)] H=3-2x[7 - 2x(3x + 1)] + 2x(5 - 3x) 1 = 4x + x[3 - x(7-x)]- 2x[4x - (x - 2)] J = 5(3x - 1)(2x + 3) - 3(2x + 3) (5-3x) + (2x + 3) K = (3x + 1)²-(x - 5)² L = (x - 9) (3x + 5)² M = (x − 3)(x + 3) = (3x + 2)(3x − 2) = (2²-9) - (9₂c²-4)= - N = (5x - 2)²-(-2x+3)² 0 = = (2x - 5)²(x + 4) = (4x²² - 20x+25) (22+4) P = (2x - 3)(2x + 3) - (x - 5)(x + 5) Q = (x + 3)² + 2(3x - 1)(x + 1) R = (2x + 1)(2x - 1)-3(x - 5)² S = (x + 5)² + 2(2x - 1)(x + 1) Exercice 2: Factoriser les expressions suivantes : A = 7x³ + 14x² + 21x B = x²y - xy² + 2x²y² C = x(3y - 4) + 4(3y - 4) D = (5x-2)(3x + 4) + (3x + 4)(-x + 3) E = (2x - 3)(x + 1) + 5(-3 + 2x) F = (x + 1)² + 3(x + 1) + x + 1 G = -3x + 4x² + 7x³ H = (x - 1)(7x+5) + 2(x-1)-(x - 1) /= (4x - 1) (7x + 3) - (x+3)(-4x + 1) /= (-x + 1)(2x + 1) + (-2x - 1)(x - 10) K = (x + 2)² - 16 L = (x + 1)² - 9 M = (x+3)²-(x + 1)² N = (2x + 1)² = (3x + 2)² 0 = (x - 5)2 – (5x+7)2 P = 16x² - 25+ (4x + 5) (3x + 1) Q = 25x²-81-7(5x + 9) R = 25x² + 70x +49-3(5x + 7) S = 36x² - 12x +1-(6x - 1)(x + 3)