Question

Tính tổng  C=1+3^2+3^4+.....+3^100

Answer 1

9C = 3² + 3⁴ + 3⁶ + ... + 3¹⁰²

9C - C = (3² + 3⁴ + 3⁶ + ... + 3¹⁰²) - (1 + 3² + 3⁴ + ... + 3¹⁰⁰)

8C = 3¹⁰² - 1

C = \(\frac{3^{102}-1}{8}\)

Answer 2

cao huệ sang ^ là mũ đó

Answer 3

C = 1 + 3² + 3⁴ + ... + 3¹⁰⁰

3C = 3 + 3³ + 3⁵ + ... + 3¹⁰¹

3C - C = (3 + 3³ + 3⁵ + ... + 3¹⁰¹) - (1 + 3² + 3⁴ + ... + 3¹⁰⁰)

2C = 3¹⁰¹ - 1

C = \(\frac{3^{101}-1}{2}\)

Answer 4

3 + 3³ + 3⁵ + ... + 3¹⁰¹ - 1 + 3² + 3⁴ + ... + 3¹⁰⁰