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10 giờ trước (8:17)

1/4 - (2x + 1/2)^2 = 0

(2x + 1/2)^2 = 1/4

(2x + 1/2)^2 = (1/2)^2

2x + 1/2 = -1/2 hoặc 2x + 1/2 = 1/2

2x + 1/2 = - 1/2

2x = - 1/2 - 1/2

2x = -1

x = -1/2

2x + 1/2 = 1/2

2x = 0

x = 0

Vậy x ∈ {-1/2; 0}

30 tháng 4 2019

c) \(\left(2x-3\right).\left(6-2x\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}2x-3=0\\6-2x=0\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}2x=3\\2x=6\end{matrix}\right.\)

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

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

e) \(2\left|\frac{1}{2}x-\frac{1}{3}\right|-\frac{3}{2}=\frac{1}{4}\)

\(\Leftrightarrow2\left|\frac{1}{2}x-\frac{1}{3}\right|=\frac{1}{4}+\frac{3}{2}=\frac{7}{4}\)

\(\Leftrightarrow\left|\frac{1}{2}x-\frac{1}{3}\right|=\frac{7}{4}:2=\frac{7}{4}.\frac{1}{2}=\frac{7}{8}\)

\(\Rightarrow\left[{}\begin{matrix}\frac{1}{2}x-\frac{1}{3}=\frac{7}{8}\\\frac{1}{2}x-\frac{1}{3}=\left(-\frac{7}{8}\right)\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=\frac{29}{12}\\x=\frac{-13}{12}\end{matrix}\right.\)

Vậy \(x\in\left\{\frac{29}{12};\frac{-13}{12}\right\}\)

30 tháng 4 2019

Mấy bài này ko quá khó, tải MathPhoto trong đt về nó tự lm

16 tháng 7 2018

a) 3x - 2 = 0    =>   3x = 2    => x = 2/3

b) 2x - 1 = 0     =>  2x = 1      =>  x = 1/2

c) 5 ( 4+2x) = 8+5x

<=> 20 + 10x = 8 + 5x

<=> 10x - 5x = 8 - 20

<=>  5x  =  -12

x = -12/5

d) \(\frac{1}{2}+\frac{3}{4}x=6-\frac{4}{5}x\)

\(\frac{3}{4}x+\frac{4}{5}x=6-\frac{1}{2}\)

\(\frac{31}{20}x=\frac{11}{2}\)

\(x=\frac{11}{2}:\frac{31}{20}=\frac{110}{31}\)

e) 3 + 2x = 4 - 8x

<=> 2x + 8x = 4 - 3

10 x = 1

x = 1/10

\(5+\frac{1}{2}\left(x+5\right)=3\)

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

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

\(x=-4-5=1\)

Vậy ......

16 tháng 7 2018

a, 3x - 2 = 0

=> 3x = 2

=> x = 2/3

vậy_

23 tháng 5 2019

\(\left(3x-1\right)\left(\frac{-1}{2}x+5\right)=0\)

\(\orbr{\begin{cases}3x-1=0\\\frac{-1}{2}x+5=0\end{cases}}\)

\(\orbr{\begin{cases}x=\frac{1}{3}\\x=10\end{cases}}\)

24 tháng 5 2019

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

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

\(\Rightarrow\frac{1}{3}:(2x-1)=\frac{-21}{4}\)

\(\Rightarrow2x-1=\frac{1}{3}:-\frac{21}{4}\)

\(\Rightarrow2x-1=\frac{1}{3}\cdot-\frac{4}{21}\)

\(\Rightarrow2x-1=\frac{-4}{63}\)

\(\Rightarrow2x=-\frac{4}{63}+1\)

\(\Rightarrow2x=\frac{59}{63}\Leftrightarrow x=\frac{59}{126}\)

12 tháng 6 2017

K chép lại đề, lm luôn nhé:

*\(\Rightarrow\) \(\left(\dfrac{7}{2}+2x\right)\cdot\dfrac{8}{3}=\dfrac{16}{3}\)

\(\Rightarrow\dfrac{7}{2}+2x=\dfrac{16}{3}:\dfrac{8}{3}=2\)

\(\Rightarrow2x=2-\dfrac{7}{2}=-\dfrac{3}{2}\)

\(\Rightarrow x=-\dfrac{3}{4}\)

* \(\Rightarrow\left|2x-\dfrac{2}{3}\right|=\dfrac{\dfrac{3}{4}-2}{2}=-\dfrac{5}{8}\)

=> K có gt x nào t/m đề

* Đề sai

* \(\Rightarrow\left[{}\begin{matrix}3x-1=0\\-\dfrac{1}{2}x+5=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=\dfrac{1}{3}\\x=10\end{matrix}\right.\)

*\(\Rightarrow\dfrac{1}{3}:\left(2x-1\right)=-5-\dfrac{1}{4}=-\dfrac{21}{4}\)

\(\Rightarrow2x-1=\dfrac{1}{3}:\left(-\dfrac{21}{4}\right)=-\dfrac{4}{63}\)

\(\Rightarrow2x=-\dfrac{4}{63}+1=\dfrac{59}{63}\)

\(\Rightarrow x=\dfrac{59}{63}:2=\dfrac{59}{126}\)

* \(\Rightarrow\left(2x+\dfrac{3}{5}\right)^2=\dfrac{9}{25}\)

\(\Rightarrow\left[{}\begin{matrix}2x+\dfrac{3}{5}=\dfrac{3}{5}\\2x+\dfrac{3}{5}=-\dfrac{3}{5}\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}2x=0\Rightarrow x=0\\2x=-\dfrac{6}{5}\Rightarrow x=-\dfrac{3}{5}\end{matrix}\right.\)

* \(\Rightarrow-5x-1-\dfrac{1}{2}x+\dfrac{1}{3}=\dfrac{3}{2}x-\dfrac{5}{6}\)

\(\Rightarrow-5x-\dfrac{1}{2}x-\dfrac{3}{2}x=-\dfrac{5}{6}+1-\dfrac{1}{3}\)

\(\Rightarrow-7x=-\dfrac{1}{6}\)

\(\Rightarrow x=-\dfrac{1}{6}:7=-\dfrac{1}{42}\)

12 tháng 6 2017

a)\(\left(3\dfrac{1}{2}+2x\right).2\dfrac{2}{3}=5\dfrac{1}{3}\)

\(\left(\dfrac{7}{2}+2x\right).\dfrac{8}{3}=\dfrac{16}{3}\)

\(\dfrac{7}{2}+2x=\dfrac{16}{3}:\dfrac{8}{3}=2\)

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

b)\(\dfrac{3}{4}-2.\left|2x-\dfrac{2}{3}\right|=2\)

\(2.\left|2x-\dfrac{2}{3}\right|=\dfrac{3}{4}-2=\dfrac{-1}{4}\)

\(\Rightarrow\left|2x-3\right|=\dfrac{-1}{8}\)

\(\Rightarrow x\in\varnothing\)

c) Đề sai,bạn có viết chữ x đâu,đó là phép tính mà.

d)\(\left(3x-1\right)\left(\dfrac{-1}{2}x+5\right)=0\)

\(\Leftrightarrow3x-1=0\Rightarrow x=\dfrac{1}{3}\)

\(\Leftrightarrow\dfrac{-1}{2}x+5=0\Rightarrow x=10\)

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

\(\dfrac{1}{3}:\left(2x-1\right)=-5-\dfrac{1}{4}=\dfrac{-21}{4}\)

\(2x-1=\dfrac{1}{3}:\dfrac{-21}{4}=\dfrac{-4}{63}\)

\(\Rightarrow2x=\dfrac{59}{63}\Rightarrow x=\dfrac{59}{126}\)

g)\(\left(2x+\dfrac{3}{5}\right)^2-\dfrac{9}{25}=0\)

\(\left(2x+\dfrac{3}{5}\right)^2=0+\dfrac{9}{25}=\dfrac{9}{25}\)

\(\dfrac{9}{25}=\left(\dfrac{3}{5}\right)^2=\left(\dfrac{-3}{5}\right)^2\)

\(th1:x=0\)

\(th2:x=\dfrac{-3}{5}\)

h)\(-5\left(x+\dfrac{1}{5}\right)-\dfrac{1}{2}\left(x-\dfrac{2}{3}\right)=\dfrac{3}{2}x-\dfrac{5}{6}\)

\(-5x+-1-\dfrac{1}{2}x-\dfrac{1}{3}=\dfrac{3}{2}x-\dfrac{5}{6}\)

\(\Leftrightarrow-5x+-1+\dfrac{5}{6}-\dfrac{1}{3}=2x\)

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

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

\(\dfrac{-1}{2}=7x\Rightarrow x=\dfrac{-1}{14}\)

17 tháng 7 2017

Ta có : \(\left|2x+4\right|+\left|4x+8\right|=0\left|2x+4\right|+\left|4x+8\right|=0\)

\(\Rightarrow\left|2x+4\right|+2.\left|2x+4\right|=\left|4x+8\right|=0\)

\(\Rightarrow\left|2x+4\right|\left(1+2\right)=0\)

=> |2x + 4| = 0

=> 2x + 4 = 0

=> 2x = -4

=> x = -2

21 tháng 7 2017

1. Đề đúng phải là thế này: \(\left|2x+4\right|+\left|4x+8\right|=0\)

\(\Rightarrow\left|2x+4\right|=\left|4x+8\right|=0\)

\(\Rightarrow2x+4=4x+8=0\)

\(\Rightarrow x=-\frac{4}{2}=-\frac{8}{4}\)

\(\Rightarrow x=-2\)

2. Sửa lại đề : \(\left|x-5\right|-\left|x-7\right|=0\)

\(\Rightarrow\left|x-5\right|=\left|x-7\right|\)

\(\Rightarrow\orbr{\begin{cases}x-5=x-7\\x-5=-\left(x-7\right)\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}-5=-7\\x-5=-x+7\end{cases}}\)

( Loại trường hợp 1)

\(\Rightarrow2x=12\)

\(\Rightarrow x=6\)

3.  \(\left|x+8\right|-\left|2x+2\right|=0\)

\(\Rightarrow\left|x+8\right|=\left|2x+2\right|\)

\(\Rightarrow\orbr{\begin{cases}x+8=2x+2\\x+8=-\left(2x+2\right)\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x+2=8\\x+8=-2x-2\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=6\\3x=-10\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=6\\x=-\frac{10}{3}\end{cases}}\)

8 tháng 8 2018

\(\left|2x\right|+2x=0\)

\(\Rightarrow\left|2x\right|=-2x\)

\(\Rightarrow2x\le0\)

\(\Rightarrow x\le0\)

Vậy \(x\le0\)

\(\left(x-1\right).\left(x+2\right)=0\)

\(\Rightarrow\orbr{\begin{cases}x-1=0\\x+2=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x=1\\x=-2\end{cases}}}\)

Vậy \(\orbr{\begin{cases}x=1\\x=-2\end{cases}}\)

\(\left|x-3\right|+x-3=0\)

\(\left|x-3\right|=-x+3\)

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

\(\Rightarrow x-3\le0\)

\(\Rightarrow x\le3\)

Vậy \(x\le3\)

\(\left(x+1\right)^3=\left(x+1\right)^5\)

\(\left(x+1\right)^5-\left(x+1\right)^3=0\)

\(\left(x+1\right)^3.\left[\left(x+1\right)^2-1\right]=0\)

\(\orbr{\begin{cases}\left(x+1\right)^3=0\\\left(x+1\right)^2-1=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x=-1\\x=0\end{cases}}}\)hoặc \(x=-2\)

Vậy \(x\in\left\{-1;0;-2\right\}\)

\(\left(x-2\right)^3=2^9\)

\(\left(x-2\right)^3=\left(2^3\right)^3\)

\(\Rightarrow x-2=2^3\)

\(x=8+2\)

\(x=10\)

Vậy \(x=10\)

Câu 6 tương tự câu 4

Tham khảo nhé~

P/S: nên chia nhỏ đăng thành nhiều bài khác nhau

19 tháng 10 2016

a=12b=18c=15

19 tháng 10 2016

Chi tiết giúp mk vs

1 tháng 8 2015

a)\(\frac{1}{3}x+\frac{2}{5}\left(x-1\right)=0\)

\(\frac{1}{3}x+\frac{2}{5}x-\frac{2}{5}=0\)

\(\frac{11}{15}x-\frac{2}{5}=0\)

\(\frac{11}{15}x=\frac{2}{5}\)

\(x=\frac{6}{11}\)

b)(2x-3)(6-2x)=0

=>2x-3=0 hoặc 6-2x=0

=>x=3/2 hoặc x=3

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

\(x:\frac{3}{4}=-\frac{11}{12}\)

\(x=-\frac{11}{16}\)

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

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

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

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

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

\(60\%x+\frac{2}{3}x=\frac{1}{3}.6\frac{1}{3}\)

\(\frac{3}{5}x+\frac{2}{3}x=\frac{19}{9}\)

\(\frac{19}{15}x=\frac{19}{9}\)

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

22 tháng 5 2020

Tìm x:
b) 1/3.x+2/5.(x-1)=0

\(<=> \dfrac{1}{3} .x +\dfrac{2}{5}x - \dfrac{2}{5} =0\)

\(<=> \dfrac{11}{15}x = \dfrac{2}{5}\)

\(<=> x= \dfrac{6}{11}\)

Vậy \( x= \dfrac{6}{11}\)
c) (2x-3).(6-2x)=0
\(<=> \begin{cases} 2x-3=0 \\ 6-2x=0 \end{cases}\) \(<=> \begin{cases} 2x=3 \\ -2x=-6 \end{cases}\) \(<=>\begin{cases} x=\dfrac{3}{2} \\ x=3 \end{cases}\)

Vậy \(x=( \dfrac{3}{2} ; 3)\)
d) -2/3-1/3.(2x-5)= 3/2

\(<=> 2x-5= \dfrac{5}{2}\)

\(<=> 2x= \dfrac{15}{2}\)

\(<=> x= \dfrac{15}{4}\)

Vậy \(x= \dfrac{15}{4}\)
f) 1/3.x-1/2=4 và 1/2 (Hỗn số ý '^')

\(<=> \dfrac{1}{3} x -\dfrac{1}{2} = \dfrac{9}{2}\)

\(<=> \dfrac{1}{3}x =5\)

\(<=> x= 15\)

Vậy \(x= 15\)

23 tháng 5 2020

Cảm ơn cậu nhiều nhé!