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18 tháng 8 2019

\(a;3^2\cdot\frac{1}{243}\cdot81^2\cdot\frac{1}{3^3}\)

\(=3^2\cdot\frac{1}{3^5}\cdot3^4\cdot\frac{1}{3^3}\)

\(=\left(3^2\cdot3^4\right)\cdot\left(\frac{1}{3^5}\cdot\frac{1}{3^3}\right)\)

\(=3^6\cdot\frac{1}{3^8}\)

\(=\frac{3^6}{3^8}\)

\(=\frac{1}{3^2}=\frac{1}{9}\)

18 tháng 8 2019

\(3^2.\frac{1}{243}.81^2.\frac{1}{3^3}\)

\(9.\frac{1}{243}.6561.\frac{1}{27}\)

\(9\)

b ) \(\left(4,2\right)^5:\left(2^3.\frac{1}{16}\right)\)

\(\left(\frac{21}{5}\right)^5:\left(8.\frac{1}{16}\right)\)

\(130691232:\frac{1}{2}\)

\(130691232\times2\)

= 261382464

Chúc bạn học tốt  !!!

5 tháng 2 2016

Câu một \(=3^2.\frac{1}{3^5}.\left(3^4\right)^2.\frac{1}{3^3}=3^{10}.\frac{1}{3^8}=3^2=9\)

Câu hai \(=\left(2^2.2^5\right):\left(2^3.\frac{1}{2^4}\right)=\frac{2^7}{\frac{2^3}{2^4}}=2^8=256\)

Chờ chút nhá :D

 

 

5 tháng 2 2016

Câu 3  \(=9-64-25^2=-680\)

Câu 4 \(=8+1-1+1=9\)

Câu 5 \(=4,75-0,37+0,125-1,28-2,5+3\frac{1}{12}=0,725+3\frac{1}{12}=3\frac{97}{120}\)

Sai thì mình xin lỗi :v, vội quá

 

13 tháng 12 2016

a) -4

b) 5.75

14 tháng 3 2020

cau phai giai ra chu

12 tháng 7 2019

a)\(\left(\frac{1}{3}\right)^{-1}-\left(-\frac{6}{7}\right)^0+\left(\frac{1}{2}\right)^4.2^3=3-1+\frac{1}{16}.8=3-1+\frac{1}{2}=\frac{5}{2}\\ \)

b)\(2^2.2^3.\left(\frac{2}{3}\right)^{-2}=2^5.\frac{9}{4}=72\)

c)\(\left(\frac{4}{3}\right)^{-2}.\left(\frac{3}{4}\right)^3:\left(\frac{-2}{3}\right)^{-3}=\left(\frac{3}{4}\right)^2.\left(\frac{3}{4}\right)^3:\left(\frac{-2}{3}\right)^{-3}=\left(\frac{3}{4}\right)^5:\left(\frac{3}{2}\right)^3=\frac{9}{128}\)

2)

\(3^{x+1}=9^x\Leftrightarrow3^x.3=9^x\Rightarrow3=9^x:3^x\Rightarrow3=3^x\Rightarrow x=1\)

\(\left(x-0,1\right)^2=6,25\Leftrightarrow\left(x-0,1\right)^2=2,5^2\Rightarrow\left(x-0,1\right)=2,5\Rightarrow x=2,5+0,1=2,6\)

\(3^{2x-1}=243\Leftrightarrow3^{2x-1}=3^5\Rightarrow2x-1=5\Rightarrow2x=6\Rightarrow x=3\)

\(\left(4x-3\right)^4=\left(4x-3\right)^2\Rightarrow x=1\)

20 tháng 2 2018

b, \(2^n\left(2^{-1}+4\right)=9\cdot2^5\)

=> \(2^n\cdot\frac{9}{2}=9\cdot2^5\)

=> \(2^n=2^6\)

Vậy \(n=6\left(tm\right)\)

20 tháng 2 2018

a, \(A=4\cdot16\cdot\frac{9}{16}\cdot\frac{4}{5}\cdot\frac{27}{8}=\frac{486}{5}=97,2\)

9 tháng 9 2019

Gửi tạm trước 2 câu !

\(a,\text{ }3^2\cdot\frac{1}{243}\cdot81^2\cdot3^{-3}=3^2\cdot\frac{1}{3^5}\cdot\left(3^4\right)^2\cdot\frac{1}{3^3}=3^2\cdot\frac{1}{3^5}\cdot3^8\cdot\frac{1}{3^3}=3^2=9\)\(b,\text{ }\frac{\left(-3\right)^{10}\cdot15^5}{25^3\cdot\left(-9\right)^7}=\frac{3^{10}\cdot\left(3\cdot5\right)^5}{\left(5^2\right)^3\cdot\left(-3\cdot3\right)^7}=\frac{3^{10}\cdot3^5\cdot5^5}{5^6\cdot3^7\cdot\left(-3\right)^7}=\frac{3^{15}\cdot5^5}{5^6\cdot3^7\cdot\left(-3\right)^7}=\frac{3}{-5}\)

9 tháng 9 2019

Trả lời :

\(a,\text{ }3^2\cdot\frac{1}{243}\cdot81^2\cdot3^{-3}=3^2\cdot\frac{1}{3^5}\cdot\left(3^4\right)^2\cdot\frac{1}{3^3}=3^2\cdot\frac{1}{3^5}\cdot3^8\cdot\frac{1}{3^3}=3^2=9\)\(b,\text{ }\frac{\left(-3\right)^{10}\cdot15^5}{25^3\cdot\left(-9\right)^7}=\frac{3^{10}\cdot\left(3\cdot5\right)^5}{\left(5^2\right)^3\cdot\left(-3\cdot3\right)^7}=\frac{3^{10}\cdot3^5\cdot5^5}{5^6\cdot3^7\cdot\left(-3\right)^7}=\frac{3^{15}\cdot5^5}{5^6\cdot3^7\cdot\left(-3\right)^7}=\frac{3}{-5}\)

12 tháng 10 2020

a) \(\left|\frac{1}{3}x-8\right|+3=15\)

\(\Leftrightarrow\left|\frac{1}{3}x-8\right|=12\)

\(\Leftrightarrow\orbr{\begin{cases}\frac{1}{3}x-8=-12\\\frac{1}{3}x-8=12\end{cases}}\Leftrightarrow\orbr{\begin{cases}\frac{1}{3}x=-4\\\frac{1}{3}x=20\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=-12\\x=60\end{cases}}\)

Vậy \(x\in\left\{-12;60\right\}\)

b) \(15-\left|2+3x\right|=8\)

\(\Leftrightarrow\left|2+3x\right|=7\)

\(\Leftrightarrow\orbr{\begin{cases}2+3x=-7\\2+3x=7\end{cases}}\Leftrightarrow\orbr{\begin{cases}3x=-9\\3x=5\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=-3\\x=\frac{5}{3}\end{cases}}\)

Vậy \(x\in\left\{-3;\frac{5}{3}\right\}\)

d) \(-1\frac{1}{6}-\left|5-3x\right|=\frac{2}{3}\)

\(\Leftrightarrow\frac{-7}{6}-\left|5-3x\right|=\frac{2}{3}\)

\(\Leftrightarrow\left|5-3x\right|=\frac{-7}{6}-\frac{2}{3}\)

\(\Leftrightarrow\left|5-3x\right|=\frac{-11}{6}\)

Vì \(\left|5-3x\right|\ge0\forall x\)

mà \(\frac{-11}{6}< 0\)\(\Rightarrow\)Vô lý 

Vậy \(x\in\varnothing\)

12 tháng 10 2020

e) \(\left(\frac{3}{7}\right)^{20}:\left(\frac{9}{49}\right)^6=\left(\frac{3}{7}\right)^{20}:\left[\left(\frac{3}{7}\right)^2\right]^6=\left(\frac{3}{7}\right)^{20}:\left(\frac{3}{7}\right)^{2.6}\)

\(=\left(\frac{3}{7}\right)^{20}:\left(\frac{3}{7}\right)^{12}=\left(\frac{3}{7}\right)^8\)

g) \(4.2^5:\left(2^3.1^{16}\right)=2^2.2^5:2^3=2^4=16\)