The formula of finding the sum of the first n terms in the equal ratio sequence

The first term is a and the common ratio is Q
The sum is a (1-Q ^ n) / (1-Q)
You can get it by setting the sum to a and calculating QA

RELATED INFORMATIONS

1. By using the first n terms of the equal ratio sequence and the formula, it is proved that: a^n+a^n-1*b+a^n-2*b^2+… +b^n=a^n+1-b^n+1/a-b
2. What is the formula of the sum of the first n terms of an equal ratio sequence?
3. 3, if the sum of the first n terms of the equal ratio sequence {an} is Sn = 3 ^ n + A, then a is an=sn-sn-1=2x3 n-1 ,a1=s1 ,2=3+a ,a=1 The answer is - 1 or 1,
4. What is 3 + 1-5 + 0-0 + 4
5. What is (- 0.5) + 3 and 1 / 4 + 2.75 + (- 5 and 1 / 2)?
6. How much plus 0.25 divided by 3.5 times 4.8 divided by 0.8 equals 1.2
7. Given that a square plus b square equals 25 and a × B equals 12, find the square of (1) a + B and (2) a-b
8. The second power of 2-0 is equal to 4, equal to 1 * 4, the second power of 4-2 is equal to 12, equal to 3 * 4, the second power of 6-4 is equal to 20, equal to 5 * 4 What rule do you find? Write numbers in letters
9. 1+2+3+4+5+…… +100 = how much
10. 1+2+3+4+5+6…… How much does it add up to 10000? The result is calculated
11. Calculation: (- 4 square + 6) × (1 / 5-3 / 2)
12. The square of 1 - the square of 2 + the square of 3 - the square of 4 + the square of 5 - the square of 6 + +The square of 99
13. Calculation: 12-22 + 32-42 + 52-62 + +20012-20022+20032-20042．______
14. Square of - 5 + 2 × (- 3) square - 7 × (- 1 / 3) square=
15. (√ 5 + 1) (√ 5-1) = (2 - √ 7) (√ 7 + 2) = (2 √ 3 + 1) square (7 - √ 3) (2 √ 3 + 1)= (√ 5 + 1) (√ 5-1) = (2 - √ 7) (√ 7 + 2) = (2 √ 3 + 1) square =? （7-√3)(2√3+1)=
16. 2. (3 √ 5 + 2 √ 6) (2 √ 6-3 √ 5) 3.√2（√2-√6）+（1+√3）（1-√3） 4.（2√3-3√2）（2√2+√3）
17. 1 = 1 square 1 + 3 = 2 square 1 + 3 + 5 = 3 square How to do it? Help ～
18. Help to use mathematical induction to prove that the square of 1 / 2 + 1 / 3 is always less than 1 when it is added to the square of 1 / n Notice that it's 1 / 2!
19. Why 1 + 3 + +What about the square of (2n-5) + (2n-3) = (n-1)?
20. 1 + 3 + 5 + 7 +. + (2n-1) = the square of n Is this formula right?