K
Khách

Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.

=>0,2x+0,4-0,5x=0,25-0,5x+0,25

=>0,2x+0,4=0,5

=>0,2x=0,1

=>x=1/2

21 tháng 1 2018

a) \(\dfrac{x}{3}-\dfrac{2x+1}{2}=\dfrac{x}{6}-x\)

\(\Leftrightarrow\dfrac{2x}{6}-\dfrac{3\left(2x+1\right)}{6}=\dfrac{x}{6}=\dfrac{6x}{6}\)

\(\Leftrightarrow2x-3\left(2x+1\right)=x-6x\)

\(\Leftrightarrow2x-6x-3=x-6x\)

\(\Leftrightarrow2x-6x-x+6x=3\)

\(\Leftrightarrow x=3\)

\(S=\left\{3\right\}\)

b) \(\dfrac{2+x}{5}-0,5x=\dfrac{1-2x}{4}+0,25\)

\(\Leftrightarrow\dfrac{4\left(2+x\right)}{20}-\dfrac{10x}{20}=\dfrac{5\left(1-2x\right)}{20}+\dfrac{5}{20}\)

\(\Leftrightarrow4\left(2+x\right)-10x=5\left(1-2x\right)+5\)

\(\Leftrightarrow8+4x-10x=5-10x+5\)

\(\Leftrightarrow4x-10x+10x=5+5-8\)

\(\Leftrightarrow4x=2\)

\(\Leftrightarrow x=\dfrac{1}{2}\)

\(S=\left\{\dfrac{1}{2}\right\}\)

22 tháng 4 2017

a)X= 3

b)X= 0,5

25 tháng 1 2022

\(\dfrac{2+x}{5}-0,5x=\dfrac{1-2x}{4}+0,25\)

\(\Leftrightarrow\dfrac{2+x}{5}-\dfrac{x}{2}=\dfrac{1-2x}{4}+\dfrac{1}{4}\)

\(\Leftrightarrow\dfrac{2+x}{5}-\dfrac{x}{2}=\dfrac{1-2x+1}{4}\)

\(\Leftrightarrow\dfrac{2+x}{5}-\dfrac{x}{2}=\dfrac{2-2x}{4}\)

\(\Leftrightarrow\dfrac{2+x}{5}=\dfrac{1-x}{2}+\dfrac{x}{2}\)

\(\Leftrightarrow\dfrac{2+x}{5}=\dfrac{1-x+x}{2}\)

\(\Leftrightarrow\dfrac{2+x}{5}=\dfrac{1}{2}\)

\(\Leftrightarrow2\left(2+x\right)=5\\ \Leftrightarrow2x+4-5=0\\ \Leftrightarrow2x-1=0\\ \Leftrightarrow x=\dfrac{1}{2}\)

25 tháng 1 2022

\(PT.\Rightarrow\) \(\dfrac{8+4x-10x-5+10x-5}{20}=0.\Rightarrow4x=2.\Leftrightarrow x=\dfrac{1}{2}.\)

18 tháng 9 2021

\(\dfrac{x+2}{x-2}-\dfrac{2}{x^2-2x}=\dfrac{1}{x}\left(đk:x\ne0,x\ne2\right)\)

\(\Leftrightarrow\dfrac{\left(x+2\right)x-2}{x\left(x-2\right)}=\dfrac{x^2-2x}{x\left(x-2\right)}\)

\(\Leftrightarrow x^2+2x-2=x^2-2x\)

\(\Leftrightarrow4x=2\Leftrightarrow x=\dfrac{1}{2}\)

18 tháng 9 2021

Cho mình sửa lại nhé:

\(\dfrac{x+2}{x-2}-\dfrac{2}{x^2-2x}=\dfrac{1}{x}\left(đk:x\ne0,x\ne2\right)\)

\(\Leftrightarrow\dfrac{\left(x+2\right)x-2}{x\left(x-2\right)}=\dfrac{x-2}{x\left(x-2\right)}\)

\(\Leftrightarrow x^2+2x-2=x-2\)

\(\Leftrightarrow x^2+x=0\)

\(\Leftrightarrow x\left(x+1\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0\left(ktm\right)\\x=-1\left(tm\right)\end{matrix}\right.\)

15 tháng 2 2022

\(Đk:\) \(x\ne1,x\ne2,x\ne3\)

\(\Rightarrow\dfrac{x+4}{\left(x-2\right)\left(x-1\right)}+\dfrac{x+1}{\left(x-3\right)\left(x-1\right)}=\dfrac{2x+5}{\left(x-3\right)\left(x-1\right)}\)

\(\Rightarrow\dfrac{\left(x+4\right)\cdot\left(x-3\right)+\left(x+1\right)\left(x-2\right)}{\left(x-2\right)\left(x-1\right)\left(x-3\right)}=\dfrac{\left(2x+5\right)\left(x-2\right)}{\left(x-3\right)\left(x-1\right)\left(x-2\right)}\)

\(\Rightarrow x^2-3x+4x-12+x^2-2x+x-2=2x^2-4x+5x-10\)

\(\Rightarrow0x-14=x-10\)

\(\Rightarrow x=-4\left(tmđk\right)\)

a: \(\Leftrightarrow4\left(2x+1\right)-3\left(6x-1\right)=2x+1\)

=>8x+4-18x+3=2x+1

=>-10x+7=2x+1

=>-12x=-6

hay x=1/2

b: \(\Leftrightarrow4x^2-12x+7x-21-x^2=3x^2+6x\)

=>5x-21=6x

=>-x=21

hay x=-21

11 tháng 11 2021

1: \(\Leftrightarrow x^2-6x=x^2-7x+10\)

hay x=10

21 tháng 1 2022

a) \(\dfrac{x+1}{4}-\dfrac{5+2x}{8}=\dfrac{3-4x}{2}\)

\(\dfrac{2\left(x+1\right)}{8}-\dfrac{5+2x}{8}=\dfrac{4\left(3-4x\right)}{8}\) 

⇔ 2x + 2 - 5 - 2x = 12 -16x

⇔ 16x = 15 

⇔ x = 15/16

b) \(\dfrac{4-3x}{5}-\dfrac{4-x}{10}=\dfrac{x+2}{2}\)

\(\dfrac{2\left(4-3x\right)}{10}-\dfrac{4-x}{10}=\dfrac{5\left(x+2\right)}{10}\)

⇔ 8 - 6x - 4 + x = 5x + 10

⇔ 10x = -6

⇔ x = -6/10

21 tháng 1 2022

Câu 1:

x + 1/4 - 5 + 2x/8 = 3 - 4x/2

<=> 2x + 2/8 - 5 + 2x/8 = 12 - 16x/8

<=> 2x + 2 - 5 - 2x = 12 - 16x

<=> -3 = 12 - 16x <=> 15 = 16x <=> x = 15/16

Câu 2:

4 - 3x/5 - 4 - x/10 = x + 2/2

<=> 8 - 6x/10 - 4 - x/10 = 5x + 10/10

<=> 8 - 6x - 4 + x = 5x + 10

<=> 4 - 5x = 5x + 10

<=> 4 = 10x + 10 <=> 10x = -6 <=> x = -3/5

11 tháng 1 2022

\(\dfrac{2x+1}{3x+2}=\dfrac{x-1}{x-2}\) (đk: x≠ 2; \(-\dfrac{2}{3}\) )

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

⇔ \(2x^2+x-4x-2=3x^2+2x-3x-2\)

⇔ \(3x^2-x-2-2x^2+3x+2=0\)

⇔ \(x^2+2x=0\)

⇔ \(x\left(x+2\right)=0\)

⇒ \(\left[{}\begin{matrix}x=0\left(TM\right)\\x=-2\left(TM\right)\end{matrix}\right.\)

Vậy \(S=\left\{0;-2\right\}\)

\(\Leftrightarrow3x^2-3x+2x-2=2x^2-4x+x-2\)

\(\Leftrightarrow x^2+2x=0\)

=>x(x+2)=0

=>x=0 hoặc x=-2

1:

a: =>28x-8=9x+3

=>19x=11

=>x=11/19

b: =>(3x-1)(x-1)=(2x+1)(x+1)

=>3x^2-4x+1=2x^2+3x+1

=>x^2-7x=0

=>x=0 hoặc x=7