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30 tháng 7 2023

\(\left(2x-3\right)^2=\dfrac{4}{25}\\ \Rightarrow\left(2x-3\right)^2=\left(\pm\dfrac{2}{5}\right)^2\\ \Rightarrow\left[{}\begin{matrix}2x-3=\dfrac{2}{5}\\2x-3=-\dfrac{2}{5}\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}2x=\dfrac{17}{5}\\2x=\dfrac{13}{5}\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{17}{10}\\x=\dfrac{13}{10}\end{matrix}\right.\)

30 tháng 7 2023

\(\left(2x-3\right)^2=\dfrac{4}{25}\\ \Leftrightarrow\left(2x-3\right)^2=\left(\dfrac{2}{5}\right)^2\\ \Leftrightarrow\left[{}\begin{matrix}2x-3=\dfrac{2}{5}\\-2x+3=\dfrac{2}{5}\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}2x=\dfrac{17}{5}\\-2x=-\dfrac{13}{5}\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=\dfrac{17}{10}\\x=\dfrac{13}{10}\end{matrix}\right.\)

Vậy...

1: \(=\dfrac{1}{4}:\dfrac{-1}{4}-2\cdot\dfrac{-1}{8}+5-4\)

\(=-1+1+\dfrac{1}{4}=\dfrac{1}{4}\)

2: \(=5^{20}\cdot\dfrac{1}{5^{20}}+\left(\dfrac{3}{8}\cdot\dfrac{4}{3}\right)^8-1=1-1+\dfrac{1}{2}^8=\dfrac{1}{2^8}\)

18 tháng 12 2022

a: =>10căn x=30

=>căn x=3

=>x=9

c: =>|1/2x-3/4|=1/2

=>1/2x-3/4=1/2 hoặc 1/2x-3/4=-1/2

=>1/2x=5/4 hoặc 1/2x=1/2

=>x=1 hoặc x=5/2

18 tháng 12 2022

cảm ơn bạn nhiều :)

22 tháng 6 2016

\(a,\left(\frac{3}{8}+-\frac{3}{4}+\frac{7}{12}\right):\frac{5}{6}+\frac{1}{2}\)

   =  \(\left(-\frac{3}{8}+\frac{7}{12}\right):\frac{5}{6}+\frac{1}{2}\)

    = \(\frac{5}{24}:\frac{5}{6}+\frac{1}{2}\)

     = \(\frac{1}{4}+\frac{1}{2}\)

      =  \(\frac{3}{4}\)

b)\(-\frac{7}{3}.\frac{5}{9}+\frac{4}{9}.\left(-\frac{3}{7}\right)+\frac{17}{7}\)

    =\(-\frac{35}{27}+\left(-\frac{4}{21}\right)+\frac{17}{7}\)

   = \(-\frac{35}{27}+\frac{47}{21}\)

   =        \(\frac{178}{189}\)

c) \(\frac{117}{13}-\left(\frac{2}{5}+\frac{57}{13}\right)\)

  = \(\frac{117}{13}-\frac{311}{65}\)

 =       \(\frac{274}{65}\)

d) \(\frac{2}{3}-0,25:\frac{3}{4}+\frac{5}{8}.4\)

\(\frac{2}{3}-\frac{1}{4}:\frac{3}{4}+\frac{5}{8}.4\)

\(\frac{2}{3}-\frac{1}{3}+\frac{5}{2}\)

=     \(\frac{1}{3}+\frac{5}{2}\)

=         \(\frac{17}{6}\)

30 tháng 8 2019

a) 2x.3/5 - 5x = 3/2 - 7x

6x/5 - 5x = 3/2 - 7x

-19x/5 = 3/2 - 7x

-19x = 15/2 - 35x

-19x + 35x = 15/2

16x = 15/2

x = 15/2 : 16

x = 15/32

b) (x - 1/5)2 = 4/25

(x - 1/5)2 = (+-2/5)2

x - 1/5 = +-2/5

x - 1/5 = 2/5 hoặc x - 1/5 = -2/5 

x = 2/5 + 1/5         x = -2/5 + 1/5

x = 3/5                  x = -1/5

26 tháng 12 2017

\(a,\left(\dfrac{2}{3}\right)^x=\left(\dfrac{4}{9}\right)^4.\)

\(\left(\dfrac{2}{3}\right)^x=\left[\left(\dfrac{2}{3}\right)^2\right]^4.\)

\(\left(\dfrac{2}{3}\right)^x=\left(\dfrac{2}{3}\right)^8\Rightarrow x=8.\)

Vậy.....

\(b,\left(2x-1\right)^2=25.\)

\(\left(2x-1\right)^2=\left(\pm5\right)^2.\)

\(\Rightarrow\left(2x-1\right)=\pm5.\)

+) Xét \(2x-1=5\), ta có:

\(2x-1=5.\)

\(\Rightarrow2x=6.\)

\(\Rightarrow x=3.\)

+) Xét \(2x-1=-5\), ta có:

\(2x-1=-5.\)

\(\Rightarrow2x=-4.\)

\(\Rightarrow x=-2.\)

Vậy.....

17 tháng 12 2022

a: \(\Leftrightarrow4^{x-5}\cdot17=68\)

=>4^x-5=4

=>x-5=1

=>x=6

b: \(\Leftrightarrow\dfrac{1}{3}:\left|2x-1\right|=\dfrac{1}{3}+\dfrac{2}{3}=1\)

=>|2x-1|=1/3

=>2x-1=1/3 hoặc 2x-1=-1/3

=>x=2/3 hoặc x=1/3

c: =>|2x-2|=|3x+15|

=>3x+15=2x-2 hoặc 3x+15=-2x+2

=>x=-17 hoặc x=-13/5

18 tháng 7 2019

\(a,\left(x-3\right)^2=1\)

=> \(\sqrt{\left(x-3\right)^2}=\sqrt{1}\)

=> \(\left|x-3\right|=1\)

=> \(\left[{}\begin{matrix}x-3=1\\x-3=-1\end{matrix}\right.\)

=> \(\left[{}\begin{matrix}x=1+3=4\\x=-1+3=2\end{matrix}\right.\)

Vậy \(x\in\left\{4;2\right\}\)

\(\left(2x+1\right)^3=-8\)

=> \(\sqrt[3]{\left(2x+1\right)^3}=\sqrt[3]{-8}\)

=> \(2x+1=-2\)

=> \(2x=-2-1=-3\)

=> \(x=-3:2=-\frac{3}{2}\)

Vậy \(x\in\left\{-\frac{3}{2}\right\}\)

\(c,\left(x-\frac{1}{4}\right)^2=\frac{1}{25}\)

=> \(\sqrt{\left(x-\frac{1}{4}\right)^2}=\sqrt{\frac{1}{25}}\)

=> \(\left|x-\frac{1}{4}\right|=\frac{1}{5}\)

=> \(\left[{}\begin{matrix}x-\frac{1}{4}=\frac{1}{5}\\x-\frac{1}{4}=-\frac{1}{5}\end{matrix}\right.\)

=> \(\left[{}\begin{matrix}x=\frac{1}{5}+\frac{1}{4}=\frac{9}{20}\\x=-\frac{1}{5}+\frac{1}{4}=\frac{1}{20}\end{matrix}\right.\)

Vậy \(x\in\left\{\frac{9}{20};\frac{1}{20}\right\}\)

18 tháng 7 2019
https://i.imgur.com/qYwoN04.jpg

2: =>(3x-7)^2=25/144=(5/12)^2

=>3x-7=5/12 hoặc 3x-7=-5/12

=>3x=5/12+7=89/12 hoặc 3x=7-5/12=79/12

=>x=89/36 hoặc x=79/36

3:Sửa đề: |2x-3|=|x+1|

=>2x-3=x+1 hoặc 2x-3=-x-1

=>x=4 hoặc 3x=2

=>x=2/3 hoặc x=4

4: =>3x+1=5 hoặc 3x+1=-5

=>3x=4 hoặc 3x=-6

=>x=-2 hoặc x=4/3

1: =>\(2x-7=\sqrt[3]{\dfrac{26}{63}}\)

=>\(2x=\sqrt[3]{\dfrac{26}{63}}+7\)

=>\(x=\dfrac{1}{2}\cdot\left(\sqrt[3]{\dfrac{26}{63}}+7\right)\)