K
Khách
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Các câu hỏi dưới đây có thể giống với câu hỏi trên
1 tháng 12 2022
a: \(\Leftrightarrow\dfrac{3}{4}:\dfrac{22}{9}-\left|3x-\dfrac{8}{3}\right|=\dfrac{3}{4}\)
\(\Leftrightarrow\left|3x-\dfrac{8}{3}\right|=\dfrac{3}{4}\cdot\dfrac{9}{22}-\dfrac{3}{4}=\dfrac{3}{4}\cdot\dfrac{-13}{22}=\dfrac{-39}{88}\)(loại)
b: \(\Leftrightarrow\left[{}\begin{matrix}3x-2=x-\dfrac{1}{3}\\3x-2=\dfrac{1}{3}-x\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}2x=\dfrac{5}{3}\\4x=\dfrac{7}{3}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{5}{6}\\x=\dfrac{7}{12}\end{matrix}\right.\)
27 tháng 11 2022
b: =>(3x-1)(3x+1)(2x+3)=0
hay \(x\in\left\{\dfrac{1}{3};-\dfrac{1}{3};-\dfrac{3}{2}\right\}\)
c: \(\Leftrightarrow\left|2x-\dfrac{1}{3}\right|=\dfrac{5}{6}+\dfrac{3}{4}=\dfrac{19}{12}\)
=>2x-1/3=19/12 hoặc 2x-1/3=-19/12
=>2x=23/12 hoặc 2x=-15/12=-5/4
=>x=23/24 hoặc x=-5/8
d: \(\Leftrightarrow-\dfrac{5}{6}\cdot x+\dfrac{3}{4}=-\dfrac{3}{4}\)
=>-5/6x=-3/2
=>x=3/2:5/6=3/2*6/5=18/10=9/5
e: =>2/5x-1/2=3/4 hoặc 2/5x-1/2=-3/4
=>2/5x=5/4 hoặc 2/5x=-1/4
=>x=5/4:2/5=25/8 hoặc x=-1/4:2/5=-1/4*5/2=-5/8
f: =>14x-21=9x+6
=>5x=27
=>x=27/5
h: =>(2/3)^2x+1=(2/3)^27
=>2x+1=27
=>x=13
i: =>5^3x*(2+5^2)=3375
=>5^3x=125
=>3x=3
=>x=1
24 tháng 9 2022
1: \(\Leftrightarrow3x+4=2\)
=>3x=-2
=>x=-2/3
2: \(\Leftrightarrow7x-7=6x-30\)
=>x=-23
3: =>\(5x-5=3x+9\)
=>2x=14
=>x=7
4: =>9x+15=14x+7
=>-5x=-8
=>x=8/5
28 tháng 6 2017
a) |2x - 1| = 3x + 2
<=> \(\left[{}\begin{matrix}2x-1=3x+2\\2x-1=-3x-2\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}-3=x\\5x=-1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-3\\x=-\dfrac{1}{5}\end{matrix}\right.\)
b) \(2x-\dfrac{4}{3}-1\dfrac{2}{3}=1\)
\(2x-\dfrac{4}{3}-\dfrac{5}{3}=1\)
\(2x-\dfrac{9}{3}=1\)
\(2x-3=1\)
<=> x = 4 : 2 = 2
c) \(\left|3x-\dfrac{1}{4}\right|=x-1\dfrac{3}{4}\)
\(\Leftrightarrow\left[{}\begin{matrix}3x-\dfrac{1}{4}=x-1\dfrac{3}{4}\\3x-\dfrac{1}{4}=-x+1\dfrac{3}{4}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}2x=-\dfrac{7}{4}+\dfrac{1}{4}\\4x=\dfrac{7}{4}+\dfrac{1}{4}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}2x=-\dfrac{3}{2}\\4x=2\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{3}{4}\\x=\dfrac{1}{2}\end{matrix}\right.\)
28 tháng 6 2017
a, \(\dfrac{5}{6}-\left|2-x\right|=\dfrac{1}{3}\Rightarrow\dfrac{5}{6}-\dfrac{1}{3}=\left|2-x\right|\)
<=> \(\dfrac{1}{2}=\left|2-x\right|\) \(\Leftrightarrow\left[{}\begin{matrix}2-x=\dfrac{1}{2}\\2-x=\dfrac{-1}{2}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{3}{2}\\x=\dfrac{5}{2}\end{matrix}\right.\)
==================
Mấy câu sau tương tự thôi
21 tháng 1 2018
a)\(\dfrac{3}{2}hay\dfrac{-3}{2}\)
b)\(\dfrac{13}{20}hay\dfrac{-13}{20}\)
c)\(\dfrac{11}{6}hay\dfrac{-11}{6}\)
d)\(\dfrac{4}{3}hay\dfrac{-4}{3}\)
e)\(\dfrac{1}{5}hay\dfrac{-1}{5}\)
Đây là câu trả lời của mình
Hay có nghĩa là hoặc
10 tháng 9 2017
a/ \(\dfrac{1}{3}-\dfrac{2}{5}+3x=\dfrac{3}{4}\)
\(\Leftrightarrow\dfrac{-1}{15}+3x=\dfrac{3}{4}\)
\(\Leftrightarrow3x=\dfrac{49}{60}\)
\(\Leftrightarrow x=\dfrac{49}{180}\)
Vậy....
b/ \(\dfrac{3}{2}-1+4x=\dfrac{2}{3}-7x\)
\(\Leftrightarrow\dfrac{1}{2}+4x=\dfrac{2}{3}-7x\)
\(\Leftrightarrow4x+7x=\dfrac{2}{3}-\dfrac{1}{2}\)
\(\Leftrightarrow11x=\dfrac{1}{6}\)
\(\Leftrightarrow x=\dfrac{1}{66}\)
Vậy....
c/ \(2\left(\dfrac{3}{4}-5x\right)=\dfrac{4}{5}-3x\)
\(\Leftrightarrow\dfrac{3}{2}-10x=\dfrac{4}{5}-3x\)
\(\Leftrightarrow-10x+3x=\dfrac{4}{5}-\dfrac{3}{2}\)
\(\Leftrightarrow-7x=-\dfrac{7}{10}\)
\(\Leftrightarrow x=-\dfrac{1}{10}\)
Vậy .....
10 tháng 9 2017
d/ \(4\left(\dfrac{1}{2}-x\right)-5\left(x-\dfrac{3}{10}\right)=\dfrac{7}{4}\)
\(\Leftrightarrow2-4x-5x-\dfrac{3}{2}=\dfrac{7}{4}\)
\(\Leftrightarrow2+\left(-4x\right)+\left(-5x\right)+\left(\dfrac{-3}{2}\right)=\dfrac{7}{4}\)
\(\Leftrightarrow-9x+\dfrac{1}{2}=\dfrac{7}{4}\)
\(\Leftrightarrow-9x=\dfrac{5}{4}\)
\(\Leftrightarrow x=-\dfrac{5}{36}\)
18 tháng 6 2018
Bài 1:
1)
\(\dfrac{3x+2}{4}\) = \(\dfrac{5x-3}{3}\)
<=> 3(3x + 2) = 4(5x - 3)
<=> 9x + 6 = 20x - 12
<=> 6 +12 = 20x - 9x
<=> 11x = 18
<=> x = \(\dfrac{18}{11}\)
Vậy: x = \(\dfrac{18}{11}\)
2)
\(\dfrac{x-1}{3x+2}\)= \(\dfrac{1}{5}\)
<=> 5(x - 1) = 3x + 2
<=> 5x - 5 = 3x + 2
<=> 5x - 3x = 2 +5
<=> 2x = 7
<=> x = \(\dfrac{7}{2}\)
Vậy : x = \(\dfrac{7}{2}\)
18 tháng 6 2018
Bài 1 :
1) Ta có :
\(\dfrac{3x+2}{4}=\dfrac{5x-3}{3}\\ \Leftrightarrow4\cdot\left(5x-3\right)=3\cdot\left(3x+2\right)\\ \Leftrightarrow20x-12=9x+6\\ \Leftrightarrow20x-18=9x\\ \Leftrightarrow20x-9x=18\\ \Leftrightarrow11x=18\\ \Leftrightarrow x=\dfrac{18}{11}\\ Vậy.,...\)
2) Ta có :
\(\dfrac{x-1}{3x+2}=\dfrac{1}{5}\Leftrightarrow5\cdot\left(x-1\right)=3x+2\\ \Leftrightarrow5x-5=3x+2\\ \Leftrightarrow5x-3x-5=2\\ \Leftrightarrow2x-5=2\\ \Leftrightarrow2x=7\\ \Leftrightarrow x=\dfrac{7}{2}\)
Vậy ....
Bài 2 ;
1) Áp dụng tính chất của dãy tỉ số bằng nhau ta có :
\(\dfrac{x}{3}=\dfrac{y}{4}=\dfrac{x+y}{3+4}=\dfrac{21}{7}=3\\ \Rightarrow\left\{{}\begin{matrix}x=3\cdot3=9\\y=3\cdot4=12\end{matrix}\right.\\ Vậy...\)
2) Ta có : \(3x=5y\Leftrightarrow\dfrac{x}{5}=\dfrac{y}{3}\)
Áp dụng tính chất của dãy tỉ số bằng nhau ta có :
\(\dfrac{x}{5}=\dfrac{y}{3}=\dfrac{x-y}{5-3}=\dfrac{-16}{2}=-8\\ \Rightarrow\left\{{}\begin{matrix}x=-8\cdot5=-40\\y=-8\cdot3=-24\end{matrix}\right.\\ Vậy....\)
3) Ta có : \(4x=7y\Leftrightarrow\dfrac{x}{7}=\dfrac{y}{4}=\dfrac{x^2}{7^2}=\dfrac{y^2}{4^2}=\dfrac{x\cdot y}{7\cdot4}\\ \Leftrightarrow\dfrac{x}{7}=\dfrac{y}{4}=\dfrac{112}{28}=4\\ \Rightarrow\left\{{}\begin{matrix}x=4\cdot7=28\\y=4\cdot4=16\end{matrix}\right.\\ Vậy...\)
29 tháng 5 2022
a: \(\dfrac{2.75}{x}=\dfrac{0.4}{1.5}=\dfrac{4}{15}\)
\(\Leftrightarrow x=\dfrac{11}{4}\cdot\dfrac{15}{4}=\dfrac{165}{16}\)
b: \(3\dfrac{1}{2}:\left(2x-3\right)=\dfrac{-3}{4}:0.2\)
\(\Leftrightarrow\dfrac{7}{2}:\left(2x-3\right)=\dfrac{-3}{4}:\dfrac{1}{5}=\dfrac{-15}{4}\)
\(\Leftrightarrow2x-3=\dfrac{7}{2}:\dfrac{-15}{4}=\dfrac{-7}{2}\cdot\dfrac{4}{15}=\dfrac{-28}{30}=\dfrac{-14}{15}\)
=>2x=-14/15+3=45/45-14/15=31/45
=>x=31/90
c: \(\dfrac{3x+2}{27}=\dfrac{3}{3x+2}\)
\(\Leftrightarrow\left(3x+2\right)^2=81\)
=>3x+2=9 hoặc 3x+2=-9
=>3x=7 hoặc 3x=-11
=>x=7/3 hoặc x=-11/3
d: \(\dfrac{5-x}{4}=\dfrac{2x+3}{2}\)
=>10-2x=8x+12
=>-10x=2
hay x=-1/5
BL
3
3 tháng 7 2017
\(\dfrac{1}{3}-\dfrac{2}{5}+3x=\dfrac{3}{4}\)
\(3x=\dfrac{1}{3}-\dfrac{2}{5}-\dfrac{3}{4}\)
\(3x=-\dfrac{49}{60}\)
\(x=-\dfrac{49}{60}:3\)
\(x=-\dfrac{49}{180}\)
3 tháng 7 2017
\(\dfrac{1}{3}-\dfrac{2}{5}+3x=\dfrac{3}{4}\)
\(\Rightarrow\dfrac{2}{5}+3x=\dfrac{1}{3}-\dfrac{3}{4}\)
\(\Rightarrow\dfrac{2}{5}+3x=-\dfrac{5}{12}\)
\(\Rightarrow3x=-\dfrac{49}{60}\)
\(\Rightarrow x=-\dfrac{49}{180}\)
15 tháng 10 2018
\(1,\dfrac{2x+4}{7}=\dfrac{4x-2}{15}=\dfrac{2.\left(2x+4\right)}{2.7}=\dfrac{4x+8}{14}\)
Áp dụng tính chất của dãy tỉ số bằng nhau ta có :
\(\dfrac{2x+4}{7}=\dfrac{4x-2}{15}==\dfrac{4x+8}{14}=\dfrac{\left(4x+8\right)-\left(4x-2\right)}{14-15}=\dfrac{10}{-1}=-10\)
\(\Rightarrow\dfrac{2x+4}{7}=-10\)
\(\Rightarrow2x+4=-10.7=-70\)
\(\Rightarrow2x=-70+4=-66\)
\(\Rightarrow x=-66:2=-33\)
Vậy \(x=-33\)
\(2,\dfrac{2x+3}{5}=\dfrac{7x-3}{15}=\dfrac{7.\left(2x+3\right)}{7.5}=\dfrac{2.\left(7x-3\right)}{2.15}=\dfrac{14x+21}{35}=\dfrac{14x-6}{30}\)
Áp dụng tính chất của dãy tỉ số bằng nhau ta có :
\(\dfrac{2x+3}{5}=\dfrac{14x+21}{35}=\dfrac{14x-6}{30}=\dfrac{\left(14x+21\right)-\left(14x-6\right)}{35-30}=\dfrac{29}{5}\)
\(\Rightarrow\dfrac{2x+3}{5}=\dfrac{29}{5}\)
\(\Rightarrow2x+3=29\)
\(\Rightarrow2x=29-3=26\)
\(\Rightarrow x=26:2=13\)
\(3,\dfrac{11x-2}{7x+5}=\dfrac{11}{8}\)
\(\Rightarrow\dfrac{11x-2}{11}=\dfrac{7x+5}{8}=\dfrac{7.\left(11x-2\right)}{7.11}=\dfrac{11.\left(7x+5\right)}{8.11}=\dfrac{77x-14}{77}=\dfrac{77x+55}{88}=\dfrac{\left(77x+55\right)-\left(77x-14\right)}{88-77}=\dfrac{69}{11}\)
\(\Rightarrow\dfrac{11x-2}{11}=\dfrac{69}{11}\)
\(\Rightarrow11x-2=69\)
\(\Rightarrow11x=69+2=71\)
\(\Rightarrow x=\dfrac{71}{11}\)
|3x-3/2|=3
3x-3/2=3 hoặc 3x-3/2=-3
TH1: 3x-3/2=3
3x=3+3/2
3x=9/2
x=9/2:3
x=3/2
TH2: 3x-3/2=-3
3x=-3+3/2
3x=-3/2
x=-3/2:3
x=-1/2
Vậy x=3/2 hoặc x=-1/2
|3x|=3+3/2 , |3x|=9/2 ,|x|=9/2 : 3, |x|=3/2,[x=3/2
[x=(-3/2)