ơ kìa số to thé

\(10\cdot10=100\)

\(100\cdot100=10000\)

Tính:

10*10=100

100*100=10000

1000*1000=1000000

10000*10000=100000000

100000*100000=10000000000

1000000*1000000=1000000000000

10000000000*10000000000=100000000000000000000

169           

100+100-100+1000-1000+10000-10000+69

=100+100-100+1000-1000+10000-10000+69

=100+69

=169

Á LỘN,TUI LÀM SAI RỒI!!!!CÂU ĐÚNG NHẤT LÀ:100+100-100+1000-1000+10000-10000+69=169

= 11111

100 + 1000 = 1100

1100+10=1110 

1110+ 10000=11110

tk minh nha abn

=11111

Chọn B

`a, 1000 : 100 = 10`

`b, 75 xx 100 = 7500`

`c, 900 xx 10 = 9000`

`d, 8 xx 100 : 10 : 10 xx 10000 = 80000`

\(a,1000:100=10\\ b,75\times100=7500\\ c,900\times10=9000\\ d,8\times100:10:10\times10000\\ =800:10:10\times10000=8\times10000=80000\)

a)\(1000:100=10\)
b)\(75\times100=7500\)

c)\(900\times10=9000\)

d)\(8\times100:10:10\times10000=8\times10000=80000\)

\(\frac{1}{10}+\frac{20}{100}+\frac{300}{1000}+\frac{40000}{100000}\)

\(=\frac{1}{10}+\frac{20}{10}+\frac{30}{10}+\frac{40}{10}\)

\(=\frac{1+2+3+4}{10}\)

\(=\frac{10}{10}\)

\(=1\)

1/10 + 20/100 + 300/1000 + 4000/10000

=1/10 + 2/10 + 3/10 + 4/10

=10/10

=1

\(\frac{1}{10}+\frac{20}{100}+\frac{300}{1000}+\frac{4000}{10000}\)

\(=\frac{1}{10}+\frac{2}{10}+\frac{3}{10}+\frac{4}{10}\)

\(=\frac{1+2+3+4}{10}\)

\(=\frac{10}{10}\)

\(=1\)

tk mk nha

=-(0,1+0,01+0,001+0,0001+0,00001)

=-0,11111

Đây là cách đơn giản nhất 

=-(0,1+0,01+0,001+0,0001+0,000001)

=-0,111101

Mk nhầm nha 

A= 9/10 + 99/100 + 999/1000 + 9999/10000

4 - A =(1 - 9/10 ) + ( 1 - 99/100 ) + (  1 - 999/1000 ) +( 1 - 9999/10000 )

4 - A = 1/0 + 1/100 + 1/1000 + 1/10000

4 - A = 1/10 - 1/10000

4 - A = 0.0999

A = 4 - 0.0999

A = 3.9001

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

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