K
Khách

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

5 tháng 8 2021

1/2x+5/2=7/2x-3/4

7/2x-1/2x=5/2+3/4

3x=13/4

x=13/12

5 tháng 8 2021

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

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

\(\Leftrightarrow-3x=-\frac{13}{4}\)

\(\Leftrightarrow x=\frac{13}{12}\)

Vậy \(x=\frac{13}{12}\).

3 tháng 5 2019

\(\frac{ }{ }\)

3 tháng 5 2019

\(1)\frac{1}{2}x-\frac{3}{5}=\frac{-4}{5}\)

\(\Rightarrow\frac{1}{2}x=\frac{-4}{5}+\frac{3}{5}\)

\(\Rightarrow\frac{1}{2}x=\frac{-1}{5}\)

\(\Rightarrow x=\frac{-1}{5}:\frac{1}{2}=\frac{-1}{5}\cdot\frac{2}{1}=\frac{-2}{5}\)

\(\Leftrightarrow x=\frac{-2}{5}\)

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

\(\Rightarrow\frac{16}{5}-\frac{7}{3}x=-\frac{8}{5}+\frac{17}{10}\)

\(\Rightarrow\frac{7}{3}x=\frac{16}{5}-\frac{-8}{5}+\frac{17}{10}\)

\(\Rightarrow\frac{7}{3}x=\frac{16}{5}+\frac{8}{5}+\frac{17}{10}\)

\(\Rightarrow\frac{7}{3}x=\frac{24}{5}+\frac{17}{10}\)

\(\Rightarrow\frac{7}{3}x=\frac{48}{10}+\frac{17}{10}\)

Đến đây tìm được rồi nhé

3,4, áp dụng bài 1,2 rồi làm :v

5 tháng 5 2019

1,\(\left(\frac{7}{2}-2x\right).\frac{4}{3}=\frac{22}{3}\)

\(x.\left(\frac{7}{2}-2\right)=\frac{22}{3}:\frac{4}{3}=\frac{22}{3}.\frac{3}{4}=\frac{11}{2}\)

\(x.\frac{3}{2}=\frac{11}{2}\)

\(x=\frac{11}{2}:\frac{3}{2}=\frac{11}{2}.\frac{2}{3}=\frac{11}{3}\)

2 tháng 5 2019

\(a,\frac{5}{7}+\frac{2}{7}:x=\frac{-11}{14}\)

\(\Rightarrow\frac{2}{7}:x=\frac{-11}{14}-\frac{5}{7}\)

\(\Rightarrow\frac{2}{7}:x=\frac{-11}{14}-\frac{10}{14}\)

\(\Rightarrow\frac{2}{7}:x=\frac{-21}{14}\)

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

Tự tìm x được rồi :v 

\(b,\frac{2}{3}x-\frac{1}{2}x=\frac{5}{12}\)

\(\Rightarrow\left[\frac{2}{3}-\frac{1}{2}\right]x=\frac{5}{12}\)

\(\Rightarrow\left[\frac{4}{6}-\frac{3}{6}\right]x=\frac{5}{12}\)

\(\Rightarrow\frac{1}{6}x=\frac{5}{12}\)

\(\Rightarrow x=\frac{5}{12}:\frac{1}{6}=\frac{5}{12}\cdot\frac{6}{1}=\frac{5}{2}\cdot\frac{1}{1}=\frac{5}{2}\)

\(c,\left[x+\frac{1}{2}\right]^2+\frac{17}{25}=\frac{26}{25}\)

\(\Rightarrow\left[x+\frac{1}{2}\right]^2=\frac{26}{25}-\frac{17}{25}\)

\(\Rightarrow\left[x+\frac{1}{2}\right]^2=\frac{9}{25}\)

\(\Rightarrow x+\frac{1}{2}=\pm\frac{3}{5}\)

\(\Rightarrow\hept{\begin{cases}x+\frac{1}{2}=\frac{3}{5}\\x+\frac{1}{2}=-\frac{3}{5}\end{cases}}\Rightarrow\hept{\begin{cases}x=\frac{1}{10}\\x=-\frac{11}{10}\end{cases}}\)

d, Tự làm

P/S : Thông cảm cho mk nhé vì máy tính mk ko bấm dấu ngoặc tròn được :v

2 tháng 5 2019

\(-3\frac{3}{5}.x=\frac{4}{15}\)

\(\frac{-18}{5}.x=\frac{4}{15}\)

\(x=\frac{4}{15}:\frac{-18}{5}\)

\(x=\frac{-2}{27}\)

\(a)x+30\%x=-1,31\)

\(\Leftrightarrow x+\frac{3x}{10}=-1,31\)

\(\Leftrightarrow10x+3x=-13,1\)

\(\Leftrightarrow13x=-13,1\Leftrightarrow x=-\frac{131}{130}\)

\(b)\left(x-\frac{1}{2}\right):\frac{1}{3}+\frac{5}{7}=9\frac{5}{7}\)

\(\Leftrightarrow\frac{2x-1}{2}.3+\frac{5}{7}=\frac{68}{7}\)

\(\Leftrightarrow\frac{6x-3}{2}=\frac{63}{7}\)

\(\Leftrightarrow\frac{6x-3}{2}=9\)

\(\Leftrightarrow6x-3=18\)

\(\Leftrightarrow x=\frac{7}{2}\)

2 tháng 5 2019

Bn làm bài 1 học kì hay 1 tiết

a:=>x^2-1-x=2x-1

=>x^2-x-1=2x-1

=>x^2-3x=0

=>x=0(loại) hoặc x=3(nhận)

b:=>x+2=0 hoặc 5-3x=0

=>x=-2 hoặc x=5/3

c:=>20(1-2x)+6x=9(x-5)-24

=>20-40x+6x=9x-45-24

=>-34x+20=9x-69

=>-43x=-89

=>x=89/43

d: =>x^2+4x+4-x^2-2x+3=2x^2+8x-4x-16-3

=>2x^2+4x-19=-2x+7

=>2x^2+6x-26=0

=>x^2+3x-13=0

=>\(x=\dfrac{-3\pm\sqrt{61}}{2}\)

e: =>(2x-3)(2x-3-x-1)=0

=>(2x-3)(x-4)=0

=>x=4 hoặc x=3/2

16 tháng 3 2023

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

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

ĐKXĐ : \(\left\{{}\begin{matrix}x\ne0\\x+1\ne0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x\ne0\\x\ne-1\end{matrix}\right.\)

Ta có : `(x-1)/x -1/(x+1) =(2x-1)/(x(x+1))`

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

`=> x^2 +x -x-1 -x-2x+1=0`

`<=> x^2 -3x =0`

`<=> x(x-3)=0`

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x-3=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\left(ktm\right)\\x=3\end{matrix}\right.\)

__

`(x+2)(5-3x)=0`

\(\Leftrightarrow\left[{}\begin{matrix}x+2=0\\5-3x=0\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=-2\\3x=5\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=-2\\x=\dfrac{5}{3}\end{matrix}\right.\)

__

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

\(\Leftrightarrow\dfrac{20\left(1-2x\right)}{12}+\dfrac{6x}{12}=\dfrac{9\left(x-5\right)}{12}-\dfrac{24}{12}\)

`<=> 2x- 40x + 6x = 9x - 45 -24`

`<=>  2x- 40x + 6x-9x + 45 +24=0`

`<=>-41x+69=0`

`<=>-41x=-69`

`<=> x=69/41`

16 tháng 3 2023

Cậu tách 2 câu 1 lượt mn trl nhanh hơn đó ạ

7/4.x+3/2=-4/5

7/4.x=-4/5-3/2

7/4.x=-23/10

x=-23/10:7/4

x=-46/35

vậy x=-46/35

1/4+3/4.x=3/4

1.x=3/4

x=3/4:1

x=3/4

vậy x=3/4

x.(1/4+1/5)-(1/7+1/8)=0

x.9/20-15/56=0

x.51/280=0

x=0:51/280

x=0

vậy x=0

3/35-(3/5+x)=2/7

(3/5+x)=3/35-2/7

(3/35+x)=-1/5

x=-1/5-3/5

x=-4/5

vậy x=-4/5

\(a,1\frac{3}{4}.x+1\frac{1}{2}=\frac{4}{5}\)

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

\(\frac{7}{4}.x=\frac{-7}{10}\)

\(x=\frac{-7}{10}:\frac{7}{4}\)

\(x=\frac{-2}{5}\)

\(b,\frac{1}{4}+\frac{3}{4}.x=\frac{3}{4}\)

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

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

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

\(x=\frac{2}{3}\)

\(c,x.\left(\frac{1}{4}+\frac{1}{5}\right)-\left(\frac{1}{7}+\frac{1}{8}\right)=0\)

\(x.\frac{9}{20}-\frac{15}{56}=0\)

\(x.\frac{9}{20}=\frac{15}{56}\)

\(x=\frac{15}{56}:\frac{9}{20}\)

\(x=\frac{25}{42}\)

\(d,\frac{3}{35}-\left(\frac{3}{5}+x\right)=\frac{2}{7}\)

\(\frac{3}{5}+x=\frac{3}{35}-\frac{2}{7}\)

\(\frac{3}{5}+x=\frac{-1}{5}\)

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

\(x=\frac{-4}{5}\)

Học tốt

17 tháng 4 2019

i don't know i mới học lớp 5

bn eie mik lớp 6 nha bn