=2.539584561

Bao nhiêu nhỉ ????????????????????

\(\frac{3\cdot11+1}{11}\cdot\frac{27\cdot46+27}{46}=\frac{34}{11}\cdot\frac{1269}{46}\)\(=\frac{21573}{253}\)

K mk nha thanks

21573 

253

\(=[3\left(\frac{1}{3}+\frac{1}{9}+\frac{1}{81}+...+\frac{1}{2187}\right)-\left(\frac{1}{3}+\frac{1}{9}+\frac{1}{81}+...+\frac{1}{2187}\right)]:2\)

\(=\left(1+\frac{1}{3}+\frac{1}{9}+...+\frac{1}{729}-\frac{1}{3}-\frac{1}{9}-\frac{1}{81}-...-\frac{1}{2187}\right):2\)

\(=\left(1-\frac{1}{2187}\right):2=\frac{2186}{2187}.\frac{1}{2}=\frac{1093}{2187}\)

=7/9*[1/3+2/3]=7/9*1=7/9

a) \(\frac{3}{5}\times\frac{8}{27}\times\frac{5}{3}\)

\(=\left(\frac{3}{5}\times\frac{5}{3}\right)\times\frac{8}{27}\)

\(=1\times\frac{8}{27}\)

\(=\frac{8}{27}\)

b) \(\frac{7}{19}\times\frac{1}{3}+\frac{7}{19}\times\frac{2}{3}\)

\(=\frac{7}{19}\times\left(\frac{1}{3}+\frac{2}{3}\right)\)

\(=\frac{7}{19}\times1\)

\(=\frac{7}{19}\)

=1093/729

ko bt có đung ko nữa

a=1 +1/3 +1/3^2 +1/3^3 +1/3^4 +1/3^5+1/3^6

3a=3 +1 +1/3 +1/3^2 + 1/3^3 +...+1/3^5

3a -a=[3 +1 +1/3 +1/3^2 +...+1/3^5] -1 -1/3 -1/3^2 -.........-1/3^6

2a =3- 1/3^6

a=[3-1/3^6] :2

a) \(11^{21}>9^{21}=\left(3^2\right)^{21}=3^{2.21}=3^{42}>3^{39}\)

b) \(5^{36}=\left(5^3\right)^{12}=125^{12}\)

\(11^{24}=\left(11^2\right)^{12}=121^{12}\)

Ta có: \(125>121\Rightarrow125^{12}>121^{12}\Rightarrow5^{36}>11^{24}\)

c) \(21^{15}=\left(3.7\right)^{15}=3^{15}.7^{15}\)

\(27^5.49^8=\left(3^3\right)^5.\left(7^2\right)^8=3^{15}.7^{16}\)

Ta có: \(7^{15}< 7^{16}\Rightarrow3^{15}.7^{15}< 3^{15}.7^{16}\Rightarrow2^{15}< 27^5.49^8\)

d) \(3^{99}=\left(3^3\right)^{33}=27^{33}>11^{21}\)

có cần phải giải ra ko

\(\frac{1}{3}+\frac{1}{9}+\frac{1}{27}+\frac{1}{81}+\frac{1}{243}\)

\(=\frac{81}{243}+\frac{27}{243}+\frac{9}{243}+\frac{3}{243}+\frac{1}{243}\)

\(=\frac{121}{243}\)

mk ko bít đúng hay ko nữa có gì mấy bạn góp ý cho mình nhé ! Thanks