Sum: SN = 1 + 3x + 5x + 7x + +﹝2n-1﹞x^n-1

Sn = 1 + 2x + 3x ^ 2 + 4x ^ 3 +... + NX ^ n-1 (1) xsn = x + 2x ^ 2 + 3x ^ 3 +... + (n-1) x ^ n-1 + NX ^ n (2) (1) - (2): (1-x) Sn = (1 + X + x ^ 2 + x ^ 3 +... + x ^ n-1) - NX ^ n = [(x ^ n) - 1] / (x-1) - NX ^ n Sn = [(x ^ n) - 1) / (x-1) ^ 2-nx ^ n / (x-1) the method used is dislocation subtraction

RELATED INFORMATIONS

1. Given the first n terms of the sequence {an} and Sn = an − 1 (a ≠ 0), then the sequence {an} () A. It must be an arithmetic sequence B. it must be an arithmetic sequence C. It must be an arithmetic sequence or an arithmetic sequence D. It is neither an arithmetic sequence nor an arithmetic sequence
2. The sum of the first n terms of the sequence {(- 1) ^ n * a ^ 4N} (a is not equal to 0) is equal to
3. In the sequence {an}, A1 is equal to 3, a (n + 1) is equal to a * a (n) + 1-A (a is not equal to 0), find a (n) and Sn
4. If the first n terms of the equal ratio sequence {an} and Sn = T5 ^ (n-2) are known, then the value of the real number T is
5. For any real number n, Sn = 2 ^ n-1, then A1 ^ 2 + A2 ^ 2 + a3 ^ 2 +... + an ^ 2 is equal to?
6. If. Sn = m * 3 ^ n + 1, then the real number M
7. The sequence {an} is an equal ratio sequence composed of real numbers, Sn = a1 + A2 + +An, then () A. Any term is not 0b. There must be one term that is not 0C. At most, there are finite terms that are 0d. Or none of them is 0, or there are infinite numbers that are 0
8. If the first n terms of the equal ratio sequence {an} and Sn = 3N + R, then r = () A. 0B. -1C. 1D. 3
9. Given that the sum of the first n terms of the sequence {an} is Sn, and Sn = n-5an-85, n ∈ n *, it is proved that {an-1} is an equal ratio sequence
10. It is known that the sum of the first n terms of the sequence {an} is Sn, and Sn = n-5an-85, n belongs to n *, it is proved that {an-1} is an equal ratio sequence
11. Sum by dislocation subtraction: sum: SN = 1 + 3x + 5x2 + 7X3 + +（2n-1）xn-1．
12. Given the function f (x) = 3x / x + 3 (x is not equal to negative 3, X belongs to R), the sequence {a small n} satisfies a small n = f (a small n minus 1) (n is greater than or equal to 2, n belongs to n) and A1 is unequal Given the function f (x) = 3x / x + 3 (x is not equal to negative 3, X belongs to R), the sequence {a small n} satisfies a small n = f (a small n minus 1) (n is greater than or equal to 2, n belongs to n) and A1 is not equal to 0 (1). Prove: the sequence {1 / a small n} is an arithmetic sequence (2). If A1 = 1 / 4, find the value of a small 50
13. When x is not equal to 1,0, 1 + 3x + 5x ^ 2 + +What is (2n-1) x ^ (n-1) equal to
14. Sum: x + 3x ^ 2 + 5x ^ 3 +... + (2n-1) x ^ n
15. 3 sum Sn = 1 (1 / 3) + 3 (1 / 3) ^ 2 + 5 (1 / 3) ^ 3 + +(2n-1) (1 / 3) ^ n (I used the method of dislocation subtraction for a long time, but I can't solve it later
16. An = n times 3 ^ n, find Sn (dislocation subtraction, detailed process)
17. It is known that {an} satisfies an = (3N + 1) 2 ^ (n + 1), and Sn is obtained by subtraction of dislocation
18. An = nx2n square for Sn dislocation subtraction
19. When an = (1 / 2n-1) * (3 / 4) ^ n, how much is Sn equal to
20. The solution is: SN = 1 × 2 + 3 × 4 + 5 × 8 +. + (2n-1) 2 * n (this represents the nth power of 2)