440. Agar geometrik progressiyada:

1) b₁=, q=2, n=6; 2) b₁= -2, q=, n=5; 3) b₁=1, q=, n=4;

4) b₁= -5, q=, n=5;      5) b₁=6, q=1, n=200;         6) b₁= -4, q=1, n=100;

           bo'lsa, uning dastlabki n ta hadining yig'indisini toping.

441. Geometrik progressiya dastlabki yettita hadining yig'indisini toping: 

1) 5,  10, 20,  ... ; 2) 2, 6, 18, ... .

442. Agar geometrik progressiyada:  

           1)      q=2, S₇=635 bo`lsa, b₁ va b₇ ni toping; 

     2)      q= -2, S₈=85 bo`lsa, b₁ va b₈ ni toping.

443. Agar geometrik progressiyada:

          1)   S_n=189,       b₁=3,    q=2;                   2)   S_n=635,   b₁=5,   q=2; 

           3)   S_n=170,       b₁=256,   q=;             4)   S_n= -99,      b₁= -9,    q= -2

bo'lsa, uning hadlari soni n ni toping.

444. Agar geometrik progressiyada:

1)  b₁=7, q =3, S = 847 bo'lsa, n va b_n ni;

2)  b₁=8, q =2, S_n = 4088 bo'lsa, n va b_n ni;

3)  b₁=2, b_n =1458, S_n = 2186 bo'lsa, n va q ni;

4)  b_t=1, b_n = 2401, S_n = 2801 bo'lsa, n va q ni   toping.

445. Agar sonlar yig'indisining qo'shiluvchilari geometrik progressiyaning ketma-ket hadlari  bo'lsa, shu yig'indini toping: 

1) 1 + 2 + 4 + ... + 128; 2) 1 + 3 + 9 + ... + 243;

3) -1 + 2 - 4 + ... + 128; 4) 5 - 15 + 45 - ... + 405.

446. Agar geometrik progressiyada: 

           1)  b₂=15, b₃ =25;                         2)  b₂=14, b₄ =686, q>0 bo`lsa,     b₅ va S₄ ni   toping;       

447. Geometrik progressiya n-hadining formulasi bilan berilgan:

1) bo'lsa, S₅ ni toping;

2) bo'lsa, S₆ ni toping.                                                    

448. Ayniyatni isbotlang:

,    bunda n daraja ko'rsatkichi va u 1 dan katta natural son.

449. Geometrik progressiyada:

1) b₃ = 135, S₃ = 195 bo'lsa, b₁ va q ni toping;

2) b₁ = 12, S₃ = 372 bo'lsa, q va b₃ ni  toping.

450. Geometrik progressiyada:

1)  b₁ =1 va b₃ + b₅ = 90 bo'lsa, q ni;

2)  b₂ = 3 va b₄ + b₆ = 60 bo'lsa, q ni;

3)  b₁ - b₃ = 15 va b₂ - b₄ = 30 bo'lsa, S₁₀ ni;

4)  b₃-b₁ = 24 va b₅ - b₁ = 624 bo'lsa, S₅ ni   toping.

TEST