Sagot :
Réponse :
bonsoir
• Developper :
D = (3 - 8x) - (4x - 7)
D = 3 - 8x - 4x - (-7)
D = 3 - 8x - 4x + 7
D = - 12x + 10
E = 7(3 - 2x) - 4x(2x - 1)
E = 7 * 3 + 7 * (-2x) - 4x * 2x - 4x * (-1)
E = 21 - 14x - 8x^2 + 4x
E = -8x^2 - 10x + 21
F = 7x - 5(2 - 9x) + 7(9x - 1)
F = 7x - 5 * 2 - 5 * (-9x) + 7 * 9x + 7 * (-1)
F = 7x - 10 + 45x + 63x - 7
F = 115x - 17
Réponse :
D = (3-8x)-5(4x-7)
= 3-8x-20x+35
= 38-28x
E = 7(3-2x)-4x(2x-1)
= 21-14x-8x²+4x
=-8x²-10x+21
F = 7x-5(2-9x)+7(9x-1)
= 7x-10+45x +63x-7
=115x -17
Explications étape par étape