Bonjour,
calculez les expressions a et b pour x=2 et x=-1 developper et reduire les expressions de a et b puis factoriser les expressions de a et b .
A=(2x-3)(4x+2)+(-2x+3)(7x-6)
A = (2 * 2 - 3)(4 * 2 + 2) + (-2 * 2 + 3)(7 * 2 - 6)
A = (4 - 3)(8 + 2) + (-4 + 3)(14 - 6)
A = 10 + (-1) * 8
A = 10 - 8
A = 2
A=(2x-3)(4x+2)+(-2x+3)(7x-6)
A = (2 * -1 - 3)(4 * -1 + 2) + (-2 * -1 + 3)(7 * -1 - 6)
A = (-2 - 3)(-4 + 2) + (2 + 3)(-7 - 6)
A = -5 * -2 + 5 * -13
A = 10 - 65
A = -55
B=25x^2 -9+(5x-3)(7x+8)
B = 25 * 2^2 - 9 + (5 * 2 - 3)(7 * 2 + 8)
B = 25 * 4 - 9 + (10 - 3)(14 + 8)
B = 100 - 9 + 7 * 22
B = 91 + 154
B = 245
B=25x^2 -9+(5x-3)(7x+8)
B = 25 * (-1)^2 - 9 + (5 * -1 - 3)(7 * -1 + 8)
B = 25 - 9 + (-5 - 3)(-7 + 8)
B = 16 - 8
B = 8
Developper :
A=(2x-3)(4x+2)+(-2x+3)(7x-6)
A = 8x^2 + 4x - 12x - 6 - 14x^2 + 12x + 21x - 18
A = -6x^2 + 25x - 24
B=25x^2 -9+(5x-3)(7x+8)
B = 25x^2 - 9 + 35x^2 + 40x - 21x - 24
B = 60x^2 + 19x - 33
Factoriser :
A=(2x-3)(4x+2)+(-2x+3)(7x-6)
A = -(-2x + 3)(4x + 2) + (-2x + 3)(7x - 6)
A = (-2x + 3)(-4x - 2 + 7x - 6)
A = (-2x + 3)(3x - 8)
B=25x^2 -9+(5x-3)(7x+8)
B = (5x)^2 - 3^2 + (5x - 3)(7x + 8)
B = (5x - 3)(5x + 3) + (5x - 3)(7x + 8)
B = (5x - 3)(5x + 3 + 7x + 8)
B = (5x - 3)(12x + 11)
