Réponse :
Bonjour,
Pour cet exercice, il faut appliquer la simple distributivité : k*(a+b) = k*a + k*b
A = -5*(x+4)
A = -5*x-5*4
A = -5x-20
B = -3*(x-2)
B = -3*x-3*(-2)
B = -3x+6
C = -4*(5x-1)
C = -4*5x-4*(-1)
C = -20x+4
D = -x*(2-4x)
D = -x*2-x*(-4x)
D = -2x+4x²
E = -2x*(x-3)
E = -2x*x-2x*(-3)
E = -2x²+6x
F = 7x*(3x-5)
F = 7x*3x+7x*(-5)
F = 21x²-35x
