1.
U_1 = 1500 + 250 = 1750
U_2 = 1750 + 250 = 2000
U_3 = 2000 + 250 = 2250
U_4 = 2250 + 250= 2500
U_5 = 2500 + 250= 2750
2.
Oui. r = 250
3.
U_n = 1500 + 250r
4.
U_10 = 1500 + 250*10 = 4000
5.
U_0 + U_1 ... + U_10 =
1500 * 11 + 250 (1+2+3+4+5+6+7+8+9+10) =
16500 + 250 (1+10 + 2+9 + 3+8 + 4+7 + 5+6) =
16500 + 250 (11 * 5) =
16500 + 5 * 1250 =
16500 + 6250=
22750 articles produits
