1 + 10 + 100 + 1000 + 10000

= 11111

nhé

101111

10C=1-1/10-1/100-1/1000-1/10000-1/100000

10C-C=(1-1/10-1/100-1/1000-1/10000-1/100000)-(1/10-1/100-1/1000-1/10000-1/100000-1/000000)

9C=1-1/10-1/10+1/1000000=800001/1000000

C=800001/1000000:9=88889/1000000

rtrrgryhyghry5yhyryry4

B = \(-\frac{1}{10}-\frac{1}{100}-\frac{1}{1000}-...-\frac{1}{1000000}\)

B = \(-\left(\frac{1}{10}+\frac{1}{10^2}+\frac{1}{10^3}+...+\frac{1}{10^6}\right)\)

Đặt A = \(\frac{1}{10}+\frac{1}{10^2}+\frac{1}{10^3}+...+\frac{1}{10^6}\)

10A = \(1+\frac{1}{10}+\frac{1}{10^2}+...+\frac{1}{10^5}\)

9A = 10A - A = \(1-\frac{1}{10^6}\)

=> A = \(\frac{1-\frac{1}{10^6}}{9}\)

=> B = \(-\left(\frac{1-\frac{1}{10^6}}{9}\right)\)

C=(0,1+0,01+0,001+...+0,000001)=-0,111111

mình ko chép đề bài

=-9100997909

= -9100997909 

k mình nha

1111111

tik mk nha bạn!

111111

\(C=-\frac{1}{10}-\frac{1}{100}-\frac{1}{1000}-\frac{1}{10000}-\frac{1}{100000}\)

\(10C=-1-\frac{1}{10}-\frac{1}{100}-\frac{1}{1000}-\frac{1}{10000}\)

\(10C-C=\left(-1-\frac{1}{10}-\frac{1}{100}-\frac{1}{1000}-\frac{1}{10000}\right)-\left(\frac{-1}{10}-\frac{1}{100}-...-\frac{1}{100000}\right)\)

\(9C=-1+\frac{1}{100000}\)

\(C=\frac{\frac{1}{100000}-1}{9}\)

cảm ơn bạn nhiều lắm Bonking mai mình cần nếu bạn giúp được mình có câu hổi mới đăng bạn giúp mình được ko

Ta có : \(B=\frac{-1}{10}-\frac{1}{100}-\frac{1}{1000}-\frac{1}{10000}-\frac{1}{100000}\)

\(\Rightarrow B=-\left(\frac{1}{10}+\frac{1}{100}+\frac{1}{1000}+\frac{1}{10000}+\frac{1}{100000}\right)\)

Đặt \(A=\frac{1}{10}+\frac{1}{100}+\frac{1}{1000}+\frac{1}{10000}+\frac{1}{100000}\)

\(\Rightarrow10A=1+\frac{1}{10}+\frac{1}{100}+\frac{1}{1000}+\frac{1}{10000}\)

\(\Rightarrow10A-A=1-\frac{1}{100000}\)

\(\Rightarrow9A=\frac{99999}{100000}\)

\(\Rightarrow A=\frac{99999}{100000}.\frac{1}{9}=\frac{11111}{100000}\)

=> B = \(-\frac{11111}{100000}\)

\(A=\frac{-1}{10}-\frac{1}{100}-\frac{1}{1000}-\frac{1}{10000}-\frac{1}{100000}\)

\(\Rightarrow A=-\left(\frac{1}{10}+\frac{1}{100}+\frac{1}{1000}+\frac{1}{10000}+\frac{1}{100000}\right)\)

\(\Rightarrow A=-\left(\frac{10000}{100000}+\frac{1000}{100000}+\frac{100}{100000}+\frac{10}{100000}+\frac{1}{100000}\right)\)

\(\Rightarrow A=-\left(\frac{10000+1000+100+10+1}{100000}\right)\)

\(\Rightarrow A=-\left(\frac{11111}{100000}\right)\)

\(\Rightarrow A=\frac{-11111}{100000}\)

-0,211111

88889/1000000=0.088889