Réponse:
A = 8-4(x-3)
A = 8-4x-4×(-3)
A= 8-4x+12
A= 8+12-4
A= 20-4x
B = 2(3-4x)+4(1-2x)
B= 2×3-2×4x+4(1-2x)
B= 6-2×4x+4(1-2x)
B= 6-8x+4(1-2x)
B= 6-8x+4-4×2x
B= 6-8x+4-8x
B= 10-8x-8x
B=10-16x
