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16 tháng 9 2023

\(\dfrac{x}{2}-\left(\dfrac{3x}{5}-\dfrac{13}{5}\right)=\dfrac{7}{5}+\dfrac{7}{10}x\\ \Rightarrow\dfrac{x}{2}-\dfrac{3x}{5}+\dfrac{13}{5}=\dfrac{7}{5}+\dfrac{7x}{10}\\ \Rightarrow\dfrac{5x}{10}-\dfrac{6x}{10}+\dfrac{26}{10}=\dfrac{14}{10}+\dfrac{7x}{10}\\ \Rightarrow\dfrac{5x}{10}-\dfrac{6x}{10}-\dfrac{7x}{10}=\dfrac{14}{10}-\dfrac{26}{10}\\ \Rightarrow\dfrac{-8x}{10}=-\dfrac{12}{10}\\ \Rightarrow\dfrac{-4x}{5}=-\dfrac{6}{5}\\ \Rightarrow-20x=-30\\ \Rightarrow x=\dfrac{3}{2}\)

2 tháng 9 2016

\(\frac{x}{2}-\left(\frac{3x}{5}-\frac{13}{5}\right)=-\left(\frac{7}{5}+\frac{7}{10}.x\right)\)
\(\frac{x}{2}-\frac{3x-13}{5}=-\frac{14+7x}{10}\)

\(\frac{5x}{10}-\frac{2\left(3x-13\right)}{10}=-\frac{14+7x}{10}\)

\(\frac{5x-6x-26}{10}=\frac{-14-7x}{10}\)

\(\Rightarrow10.\left(5x-6x-26\right)=\left(-14-7x\right).10\)

\(\Rightarrow50x-60x-260=-140-70x\)

\(\Rightarrow-10x-260=-140-70x\)

\(\Rightarrow-10x+70x=-140+260\)

\(\Rightarrow60x=120\)

\(\Rightarrow x=2\)

2 tháng 9 2016

\(\frac{x}{2}-\left(\frac{3x}{5}-\frac{13}{5}\right)=-\left(\frac{7}{5}+\frac{7}{10}x\right)\) 

\(\Leftrightarrow\frac{x}{2}-\frac{3x}{5}+\frac{13}{5}=-\frac{7}{5}-\frac{7}{10}x\) 

\(\Leftrightarrow\frac{x}{2}-\frac{3x}{5}=-\frac{7}{10}x-4\) 

\(\Leftrightarrow-\frac{7}{10}x-\frac{x}{2}+\frac{3x}{5}=4\) 

\(\Leftrightarrow x\left(-\frac{7}{10}-\frac{1}{2}+\frac{3}{5}\right)=4\) 

\(\Leftrightarrow x\left(-\frac{3}{5}\right)=4\) 

\(\Leftrightarrow x=-\frac{20}{3}\)

13 tháng 7 2019

a. x/2-3x/5+13/5=-7/5-7/10x

    -7/5-x/2+3x/5-13/5=7/10x

    -x/2+3x/5-4=7/10x

    7/10x-3x/5+x/2=-4

    7x-6x+5x/10=-4

     6x=-40

     x=-20/3

2 tháng 10 2023

`x/2-(3x/5-13/5)=7/5-7/10x`

`=>x/2-3x/5+13/5=7/5+(7x)/10`

`=>(5x)/10-(6x)/10-(7x)/10=7/5-13/5`

`=>(5x-6x-7x)/10=(7-13)/5`

`=>(-4x)/5=-6/5`

`=>4x=6`

`=>x=3/2`

2 tháng 10 2023

giúp mik câu ms đăng đk ?

 

23 tháng 6 2018

\(a,\frac{-3}{2}-2x+\frac{3}{4}=-1\)

\(\frac{-3}{2}-2x=-1-\frac{3}{4}\)

\(\frac{-3}{2}-2x=\frac{-7}{4}\)

\(2x=\frac{-7}{4}+\frac{-3}{2}\)

\(2x=\frac{-13}{4}\)

\(x=\frac{-13}{4}:2\)

\(x=\frac{-13}{4}.\frac{1}{2}\)

\(x=\frac{-13}{8}\)

5 tháng 10 2020

Bài 1 :

a) \(\frac{12}{21}-\frac{3}{7}+\left(-\frac{2}{3}\right)=\frac{4}{7}-\frac{3}{7}+\left(-\frac{2}{3}\right)=\frac{1}{7}-\frac{2}{3}=-\frac{11}{21}\)

b) \(\left(-\frac{25}{13}\right)+\left(-\frac{9}{17}\right)+\frac{12}{13}+\left(-\frac{25}{17}\right)\)

\(=\left[\left(-\frac{25}{13}\right)+\frac{12}{13}\right]+\left[\left(-\frac{9}{17}\right)+\left(-\frac{25}{17}\right)\right]\)

\(=-1+\left(-2\right)=-1-2=-3\)

c) \(\frac{5}{9}\cdot\frac{7}{13}+\frac{5}{9}\cdot\frac{9}{13}-\frac{5}{9}\cdot\frac{3}{13}=\frac{5}{9}\left(\frac{7}{13}+\frac{9}{13}-\frac{3}{13}\right)=\frac{5}{9}\cdot1=\frac{5}{9}\)

Bài 2 :

a)  \(\frac{2}{3}x+\frac{5}{7}=\frac{3}{10}\)

=> \(\frac{2}{3}x=\frac{3}{10}-\frac{5}{7}=-\frac{29}{70}\)

=> \(x=\left(-\frac{29}{70}\right):\frac{2}{3}=\left(-\frac{29}{70}\right)\cdot\frac{3}{2}=-\frac{87}{140}\)

b) \(x:\frac{5}{2}-\frac{1}{2}=-\frac{2}{3}\)

=> \(x:\frac{5}{2}=-\frac{2}{3}+\frac{1}{2}=-\frac{1}{6}\)

=> \(x=\left(-\frac{1}{16}\right)\cdot\frac{5}{2}=-\frac{5}{32}\)

c) Bạn chỉ cần xét hai trường hợp âm và dương thôi :>

a: 2x-3/2+3/4=-4

=>2x-3/4=-4

=>2x=-13/4

hay x=-13/8

b: \(\left(-\dfrac{2}{3}x-\dfrac{3}{5}\right)\cdot\left(\dfrac{-3}{2}-\dfrac{10}{3}\right)=\dfrac{2}{5}\)

\(\Leftrightarrow-\dfrac{2}{3}x-\dfrac{3}{5}=\dfrac{2}{5}:\dfrac{-29}{6}=\dfrac{-2}{5}\cdot\dfrac{6}{29}=\dfrac{-12}{145}\)

=>2/3x+3/5=12/145

=>2/3x=-15/29

hay x=-45/58

c: \(\dfrac{x}{2}-\left(\dfrac{3}{5}x-\dfrac{13}{5}\right)=-\left(\dfrac{7}{10}x+\dfrac{7}{5}\right)\)

=>1/2x-3/5x+13/5=-7/10x-7/5

=>-1/10x+7/10x=-7/5-13/5

=>3/5x=-2

hay x=-2:3/5=-10/3

=>1/2x-3/5x+13/5=7/5+7/10x

=>-1/10x-7/10x=7/5-13/5

=>-4/5x=-6/5

=>x=6/5:4/5=6/5x5/4=6/4=1,5

a, \(\left(3x-5\right)\left(x+1\right)-\left(3x-1\right)\left(x+1\right)=x-4\)

\(\Leftrightarrow\left(x+1\right)\left(3x-5-3x+1\right)=x-4\Leftrightarrow-4\left(x+1\right)=x-4\)

\(\Leftrightarrow-4x-4=x-4\Leftrightarrow-4x-x=0\Leftrightarrow x=0\)

b, \(\left(x-2\right)\left(x+3\right)-\left(x+4\right)\left(x-7\right)=5-x\)

\(\Leftrightarrow x^2+x-6-x^2-3x+28=5-x\Leftrightarrow-2x+22=5-x\Leftrightarrow x=17\)

c,  thiếu đề 

d, \(3\left(x-7\right)\left(x+7\right)-\left(x-1\right)\left(3x+2\right)=13\)

\(\Leftrightarrow3x^2-147-3x^2+x+2=13\Leftrightarrow x=11+147=158\)

NM
19 tháng 7 2021

a.\(3x^2-2x-5-\left(3x^2+2x-1\right)=x-4\)

\(\Leftrightarrow-5x=0\Leftrightarrow x=0\)

b.\(x^2+x-6-\left(x^2-3x-28\right)=5-x\)

\(\Leftrightarrow5x=-17\Leftrightarrow x=-\frac{17}{5}\)

c.\(5\left(x^2-10x+21\right)-\left(5x^2-9x-2\right)=0\)

\(\Leftrightarrow-41x+107=0\Leftrightarrow x=\frac{107}{41}\)

d.\(3\left(x^2-49\right)-\left(3x^2-x-2\right)=13\Leftrightarrow x=158\)