Sprendimas: OBhbin - 1
S_n =
| b1* ( q^n-1) |
| / (q-1) |
|
S_n =
= 
| b1* ( q^n-1) |
| / (q-1) |
S_n =
-
= 
| q^n* b1 |
| / (q-1) |
| b1 |
| / (q-1) |
S_n =
-
= 
| b1* q^n |
| / (q-1) |
| b1 |
| / (q-1) |