Sagot :
Exercice 1
A = (2x+4)(5x+3)
A = 2x*5x + 2x*3 + 4*5x + 4*3
A = 10x² + 6x + 20x + 12
A = 10x² + 26x + 12
B = (7 + x)(9x-3)
B = 7*9x + 7*(-3) + x*9x + x*(-3)
B = 63x -21 + 9x² -3x
B = 9x² + 63x -21
C = (-6+2x)(3x-1)
C = -6*3x -6*(-1) + 2x*3x + 2x*(-1)
C = -18x + 6 + 6x² - 2x
C = 6x² - 20x + 6
D = (-3x+8)(-4-5x)
D = -3x*(-4) -3x*(-5x) +8*(-4)+8*(-5x)
D = -12x -15x² -32 - 45x
D = -15x² -57x -32
E = 2(4x-3)-7(x-4)
E = 2*4x + 2*(-3) -7*x -7*(-4)
E = 8x-6 -7x + 28
E = x + 22
Exercice 2
A = (2x+4)(5x+3) + (3x+7)(5x+3)
A = (5x+3)*[(2x+4)+(3x+7)
A = (5x+3)(2x+4+3x+7)
A = (5x+3)(5x+11)
B = (4+x)(9x-3)+(4+x)(7x-8)
B = (4+x)*[(9x-3)(7x-8)]
B = (4+x)(9x-3 + 7x-8)
B = (4+x)(16x-11)
C = (2x+4)(6x+3) - (2x+4)(5x+3)
C = (2x+4)*[(6x+3)-(5x+3)]
C = (2x+4)(6x+3 - 5x+3)
C = (2x+4)(x)
D = (-3x+8)(-4-5x)-(-5x+7)(-4-5x)
D = (-4-5x)*[(-3x+8)-(-5x+7)
D = (-4-5x)(-3x+8-(-5x)+7)
D = (-4-5x)(2x+1)
Exercice 3
1.
D = (2x-3)²+(2x-3)(7x-4)
D = (2x-3)(2x-3)+(2x*7x+2x*(-4)-3*7x-3*(-4) )
D = (2x*2x+2x*(-3)-3*2x-3*(-3) )+(14x²-8x-21x+12)
D = (4x²-6x-6x+9)+(14x²-29x+12)
D = (4x²+9+14x²-29x+12)
D = 18x²-29x+21
3.
D = (2x-3)²+(2x-3)(7x-4)
D = (2x-3)(2x-3)+(2x-3)(7x-4)
D = (2*3-3)(2*3-3)+(2*3-3)(7*3-4)
D = 3*3+3*17
D = 9+51
D = 60
Je tiens a préciser que je ne suis pas sûr des résultats de factorisation surtout le dernier de l'exercice et l'exercice 3 du 3.
