Відповіді §.19 - §.20 » §.20 (3.3-4)

3. b1 = 3, b3 = 12. n = 5. b22 = b1 • b3 = 3 • 12 = 36, b2 = ±6. I. b2 = 6, q = 2. S5 = (3 •(2^5- 1))/(2-1) = 93. II. b2 = –6 q = –2 S5 = (3 •(-32-1))/(-3) = 33. 4. b3 = 18, b5 = 2, n = 5. b42 = b3 • b5 = 36. b4 = ±6. 1) b4 = 6, то q = b_4/b_3 = 6/18 = 1/3. b3 = b1, q2, b1 = 18/(1/9) = 162. S5 = (162((1/3 )^5- 1))/(1/3- 1) = (162 •(-242/243))/(-2/3) = (162 •3 •242)/(243 •2) = 242.