Réponse :
Explications étape par étape
Bonsoir
developper et réduire les expressions suivantes :
a)
7−2x×(4x−1)
= 7 - 8x^2 + 2x
= -8x^2 + 2x + 7
b)
(2x + 2)(2x - 2) - (x + 3)(2x+2)(2x−2)−(x+3)
= 4x^2 - 4 - (2x^2 + 2x + 6x + 6)(2x - 2) - x - 3
= 4x^2 - x - 7 - (2x^2 + 8x + 6)(2x - 2)
= 4x^2 - x - 7 - (4x^3 - 4x^2 + 16x^2 - 16x + 12x - 12)
= -4x^3 + 4x^2 + 4x^2 - 16x^2 - x + 16x - 12x - 7 + 12
= -4x^3 - 8x^2 + 3x + 5
c)
(8 - x) - ( - 2x + 5)(8−x)−(−2x+5)
= 8 - x - (-16x + 2x^2 + 40 - 5x) + 2x - 5
= x + 3 + 16x - 2x^2 - 40 + 5x
= -2x^2 + 22x - 37
d)
(−5×3x)(x×4)
= -15x * 4x
= -60x^2
e)
{(5x + 8)}^{2}(5x+8)2
= (25x^2 + 80x + 64)(10x + 16)
= 250x^3 + 400x^2 + 800x^2 + 1280x + 640x + 1024
= 250x^3 + 1200x^2 + 1920x + 1024
f)
(2x - 3)(5x - 1) + 8(2x−3)(5x−1)+8
= 10x^2 - 2x - 15x + 3 + 8(10x^2 - 2x - 15x + 3) + 8
= 10x^2 - 17x + 3 + 80x^2 - 16x - 120x + 24 + 8
= 90x^2 - 153x + 35
