Réponse :
1)
5(x + 4) - 4(y + 2)
= 5 * x + 5 * 4 - 4 * y + 4 * 2
= 5x + 20 - 4y + 8
= 5x + 12 - 4y
2)
-3(2 + y) + 5(x - 4)
= -3 * 2 + (-3) * y + 5 * x - 5 * 4
= -6 + (-3)y + 5x - 20
= -26 + 5x - 3y
3)
8(z + 1) - 5(y + 2)
= 8 * z + 8 * 1 - 5 * y + 5 * 2
= 8z + 8 - 5y + 10
= -2 - 5y + 8z