Sagot :
Réponse :
A = 21x²+59x+8
B = -24x²+22x+10
C = 4x²+4x+1
D = x²-13x+25
2 :
A = 20
D = 73
Explications étape par étape
A = (7x+1)(3x+8)
A = 7x*3x+7x*8+1*3x+1*8
A = 21x²+56x+3x+8
A = 21x²+59x+8
B = (6x+2)(5-4x)
B = 6x*5+6x*(-4x)+2*5+2*(-4x)
B = 30x-24x²+10-8x
B = -24x²+22x+10
C = (2x+1)²
C = 4x²+4x+1
D = (x-5)²-3x
D = x²-10x+25 -3x
D = x²-13x+25
2 :
A(pour x = 3)= (-21x+1)(-9x+8)
A = 189-168-9+8
A = 20
D = (-3-5)²-3*(-3)
D = (-3-5)²+9
D = (-8)²+9
D = 64+9
D = 73