cho M=1/3^2+2/3^3+3/3^4+…+10/3^11.Tính M 29/10/2021 Bởi Kaylee cho M=1/3^2+2/3^3+3/3^4+…+10/3^11.Tính M
M=1/3^2+2/3^3+3/3^4+…+10/3^11 3. M = 1/3+ 2/3^2 +…+ 10/ 3^10 3.M – M = ( 1/3+ 2/3^2 +…+ 10/ 3^10] – ( 1/3^2+2/3^3+3/3^4+…+10/3^11] 2. M= (1/3- 10/ 3^11] + ( 2/3^2 – 1/3^2 ]+ …………+ ( 10/3^10- 9/3^10] 2. M = ( 1/3- 10/3^11]+ 1/3^2+ 1/3^3+…+ 1/3^10 Đặt N = 1/3^2+ 1/3^3+…+ 1/3^10 3. N = 1/3+ 1/3^2+ …+ 1/3^9 3. N – N= 1/3- 1/3^10 N = ( 1/3- 1/3^10]: 2 ⇒ M = ( ( 1/3- 10/3^11]+ ( 1/3- 1/3^10]: 2} : 2 Học tốt nha! Bình luận
M=1/3^2+2/3^3+3/3^4+…+10/3^11
3. M = 1/3+ 2/3^2 +…+ 10/ 3^10
3.M – M = ( 1/3+ 2/3^2 +…+ 10/ 3^10] – ( 1/3^2+2/3^3+3/3^4+…+10/3^11]
2. M= (1/3- 10/ 3^11] + ( 2/3^2 – 1/3^2 ]+ …………+ ( 10/3^10- 9/3^10]
2. M = ( 1/3- 10/3^11]+ 1/3^2+ 1/3^3+…+ 1/3^10
Đặt N = 1/3^2+ 1/3^3+…+ 1/3^10
3. N = 1/3+ 1/3^2+ …+ 1/3^9
3. N – N= 1/3- 1/3^10
N = ( 1/3- 1/3^10]: 2
⇒ M = ( ( 1/3- 10/3^11]+ ( 1/3- 1/3^10]: 2} : 2
Học tốt nha!