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Câu d:
-1\(\frac23\) - (|2\(x\)| + \(\frac56\)) = - 2
-\(\frac53\) - |2\(x\)| - \(\frac56\) = - 2
|2\(x\)| = - \(\frac53\) - \(\frac56\) + 2
|2\(x\)| = - \(\frac52\) + 2
|2\(x\)| = - \(\frac12\) (vô lí vì trị tuyệt đối của một số luôn là một số không âm)
Không có giá trị nào của x thỏa mãn đề bài.
x ∈ ∅
Câu a:
|\(x\) - 3| = \(x\) + 4
Vì |\(x\) - 3| ≥ 0 ∀ \(x\) nên \(x\) + 4 ≥ 0 ⇒ \(x\) ≥ - 4
Với -4 ≤ \(x\) ≤ 3 ta có:
-\(x\) + 3 = \(x\) + 4
\(x\) + \(x\) = -4 + 3
2\(x\) = -1
\(x=\frac{-1}{2}\)
Với x > 3 ta có:
x - 3 = x + 4
x - x = 3 + 4
0 = 7 (vô lí)
Vậy x = -1/2 là nghiện duy nhất của phương trình.
Vậy \(x\) = -1/2
\(\left(2\frac{1}{3}+3\frac{1}{2}\right):\left(x+3\frac{1}{7}\right)+7\frac{1}{2}=1\frac{69}{86}\)
\(\left(\frac{7}{3}+\frac{7}{2}\right):\left(x+\frac{22}{7}\right)+\frac{15}{2}=\frac{155}{86}\)
\(\left(\frac{14}{6}+\frac{21}{6}\right):\left(x+\frac{22}{7}\right)+\frac{15}{2}=\frac{155}{86}\)
\(\frac{35}{6}:\left(x+\frac{22}{7}\right)=\frac{155}{86}-\frac{15}{2}\)
\(\frac{35}{6}:\left(x+\frac{22}{7}\right)=\frac{155}{86}-\frac{645}{86}\)
\(\frac{35}{6}:\left(x+\frac{22}{7}\right)=\frac{-245}{43}\)
\(x+\frac{22}{7}=\frac{35}{6}:\frac{-245}{43}=\frac{35}{6}\cdot\frac{-43}{245}\)
\(x+\frac{22}{7}=\frac{-43}{42}\)
\(x=\frac{-43}{42}-\frac{22}{7}=\frac{-43}{42}-\frac{132}{42}\)
\(x=\frac{-25}{6}\)
a, \(-\frac{5}{7}-\left(\frac{1}{2}-x\right)=-\frac{11}{4}\)
\(\frac{1}{2}-x=\frac{57}{28}\)
\(x=-\frac{43}{28}\)
b, \(\left(2x-1\right)^2-5=20\)
\(\Rightarrow\left(2x-1\right)^2=25\)
\(\Rightarrow2x-1=\pm5\)
\(\Rightarrow\left[{}\begin{matrix}2x-1=5\\2x-1=-5\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}2x=6\\2x=-4\end{matrix}\right.\) \(\Rightarrow\left[{}\begin{matrix}x=3\\x=-2\end{matrix}\right.\)
Câd
\(\frac{x-6}{4}=\frac{4}{x-6}\)
(\(x-6\))(\(x-6\)) =4.4
(\(x-6\))\(^2\) = 4\(^2\)
\(x-6=-4\) hoặc \(x\) - 6 = 4
\(x-6\) = -4
\(x=-4+6\)
\(x=2\)
\(x-6=4\)
\(x=4+6\)
\(x=10\)
Vậy \(x\) ∈ {2; 10}
b, \(\left(2x-1\right)^2-5=20\)
\(\Rightarrow\left(2x-1\right)^2=25\)
\(\Rightarrow\left(2x-1\right)^2=5^2\)
\(\Rightarrow\left[{}\begin{matrix}2x-1=6\\2x-1=-6\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}2x=7\\2x=-5\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=\frac{7}{2}\\x=-\frac{5}{2}\end{matrix}\right.\)
Vậy ...
a) \(-\frac{5}{7}-\left(\frac{1}{2}-x\right)=\frac{-11}{4}\)
\(\Rightarrow\left(\frac{1}{2}-x\right)=\left(-\frac{5}{7}\right)+\frac{11}{4}\)
\(\Rightarrow\frac{1}{2}-x=\frac{57}{28}\)
\(\Rightarrow x=\frac{1}{2}-\frac{57}{28}\)
\(\Rightarrow x=-\frac{43}{28}\)
Vậy \(x=-\frac{43}{28}.\)
b) \(\left(2x-1\right)^2-5=20\)
\(\Rightarrow\left(2x-1\right)^2=20+5\)
\(\Rightarrow\left(2x-1\right)^2=25\)
\(\Rightarrow2x-1=\pm5\)
\(\Rightarrow\left[{}\begin{matrix}2x-1=5\\2x-1=-5\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}2x=5+1=6\\2x=\left(-5\right)+1=-4\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=6:2\\x=\left(-4\right):2\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=3\\x=-2\end{matrix}\right.\)
Vậy \(x\in\left\{3;-2\right\}.\)
d) \(\frac{x-6}{4}=\frac{4}{x-6}\)
\(\Rightarrow\left(x-6\right).\left(x-6\right)=4.4\)
\(\Rightarrow\left(x-6\right).\left(x-6\right)=16\)
\(\Rightarrow\left(x-6\right)^2=16\)
\(\Rightarrow x-6=\pm4\)
\(\Rightarrow\left[{}\begin{matrix}x-6=4\\x-6=-4\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=4+6\\x=\left(-4\right)+6\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=10\\x=2\end{matrix}\right.\)
Vậy \(x\in\left\{10;2\right\}.\)
Chúc bạn học tốt!
Câu a:
2.(3\(x\) - \(\frac12\)) - 2\(x\) = \(\frac12\).(2\(x\) - 3)
6\(x\) - 1 - 2\(x\) = \(x\) - \(\frac32\)
6\(x\) - 2\(x\) - \(x\) = 1 - \(\frac32\)
4\(x\) - \(x\) = - \(\frac12\)
3\(x\) = - \(\frac12\)
\(x\) = - \(\frac12\) : 3
\(x=-\frac16\)
Vậy \(x=-\frac16\)
Câu b:
(2\(x\) - \(\frac35\))\(^2\) = \(\frac{4}{25}\)
(2\(x-\frac35\))\(^2\) = \(\left(\frac{2}{25}\right)\)\(^2\)
2\(x\) - \(\frac35\) = \(\frac25\) hoặc 2\(x\) - \(\frac35\) = - \(\frac25\)
TH: 2\(x\) - \(\frac35\) = \(\frac25\)
2\(x\) = \(\frac25+\frac35\)
2\(x\) = 1
\(x=\frac12\)
2\(x\) - \(\frac35\) = - \(\frac25\)
2\(x\) = - \(\frac25\) + \(\frac35\)
2\(x\) = \(\frac15\)
\(x\) = \(\frac{13}{25}\) : 2
\(x\) = \(\frac15\)
Vậy \(x\) ∈ {1/5; 1/2}
làm hộ mình cái để mai nộp thầy,ai nhanh và đúng thì mình k cho nha
\(a)-3\frac{1}{2}+\frac{1}{3}.\left(x-1\right)=-1\frac{1}{3}:2\frac{1}{3}\)
\(-\frac{7}{2}+\frac{1}{3}.\left(x-1\right)=-\frac{4}{3}:\frac{7}{3}\)
\(-\frac{7}{2}+\frac{1}{3}.\left(x-1\right)=-\frac{4}{7}\)
\(\frac{1}{3}.\left(x-1\right)=-\frac{4}{7}-\frac{-7}{2}\)
\(\frac{1}{3}.\left(x-1\right)=\frac{41}{14}\)
\(\Rightarrow x-1=\frac{41}{14}:\frac{1}{3}\)
\(\Rightarrow x-1=\frac{123}{14}\)
\(\Rightarrow x=\frac{123}{14}+1\)
\(\Rightarrow x=\frac{137}{14}\)
1) \(\frac{1}{3}x-\frac{2}{5}=\frac{1}{3}\)
⇒ \(\frac{1}{3}x=\frac{1}{3}+\frac{2}{5}\)
⇒ \(\frac{1}{3}x=\frac{11}{15}\)
⇒ \(x=\frac{11}{15}:\frac{1}{3}\)
⇒ \(x=\frac{11}{5}\)
Vậy \(x=\frac{11}{5}.\)
2) \(2,5:7,5=x:\frac{3}{5}\)
⇒ \(\frac{5}{2}:\frac{15}{2}=x:\frac{3}{5}\)
⇒ \(\frac{1}{3}=x:\frac{3}{5}\)
⇒ \(x=\frac{1}{3}.\frac{3}{5}\)
⇒ \(x=\frac{1}{5}\)
Vậy \(x=\frac{1}{5}.\)
4) \(\left|x\right|+\left|x+2\right|=0\)
Có: \(\left\{{}\begin{matrix}\left|x\right|\ge0\\\left|x+2\right|\ge0\end{matrix}\right.\forall x.\)
⇒ \(\left|x\right|+\left|x+2\right|=0\)
⇒ \(\left\{{}\begin{matrix}x=0\\x+2=0\end{matrix}\right.\) ⇒ \(\left\{{}\begin{matrix}x=0\\x=0-2\end{matrix}\right.\) ⇒ \(\left\{{}\begin{matrix}x=0\\x=-2\end{matrix}\right.\)
Vô lí vì \(x\) không thể nhận cùng lúc 2 giá trị khác nhau.
⇒ \(x\in\varnothing\)
Vậy không tồn tại giá trị nào của \(x\) thỏa mãn yêu cầu đề bài.
10) \(5-\left|1-2x\right|=3\)
⇒ \(\left|1-2x\right|=5-3\)
⇒ \(\left|1-2x\right|=2\)
⇒ \(\left[{}\begin{matrix}1-2x=2\\1-2x=-2\end{matrix}\right.\) ⇒ \(\left[{}\begin{matrix}2x=1-2=-1\\2x=1+2=3\end{matrix}\right.\) ⇒ \(\left[{}\begin{matrix}x=\left(-1\right):2\\x=3:2\end{matrix}\right.\)
⇒ \(\left[{}\begin{matrix}x=-\frac{1}{2}\\x=\frac{3}{2}\end{matrix}\right.\)
Vậy \(x\in\left\{-\frac{1}{2};\frac{3}{2}\right\}.\)
Chúc bạn học tốt!
9, \(13\frac{1}{3}:1\frac{1}{3}=26:\left(2x-1\right)\)
\(\frac{40}{3}:\frac{4}{3}=26:\left(2x-1\right)\)
\(10=26:\left(2x-1\right)\)
\(2x-1=26:10\)
\(2x-1=2,6\)
\(2x=2,6+1\)
\(2x=3,6\)
\(x=3,6:2\)
\(x=1,8\)

Từ đề bài ta có:
4/3x - 1/3 = (2x-1) : 3/5
=> 4/3x -1/3 = (2x-1) * 5/3
=> 4/3x -1/3= 10/3x - 5/3
Chuyển vế đổi dấu
Ta được:
=> -2x = -4/3
=> x= 2/3
Vậy x= 2/3
\(1\frac{1}{3}x=\left(2x-1\right):\left(1-\frac{2}{5}\right)\)
\(\frac{4}{3}x=\left(2x-1\right):\left(\frac{3}{5}\right)\)
\(\frac{4}{3}x.\frac{3}{5}=\left(2x-1\right)\)
\(\frac{4}{5}x=\left(2x-1\right)\)
\(x=\left(2x-1\right):\frac{4}{5}\)
\(x=\left(2x-1\right).\frac{5}{4}\)
\(x=2x.\frac{5}{4}-1.\frac{5}{4}\)
\(x=\)\(2x.\frac{5}{4}-\frac{5}{4}\)
\(x=2.\frac{5}{4}.x-\frac{5}{4}\)
\(x=\left(\frac{5}{2}.x\right)-\frac{5}{4}\)
\(x=\frac{5}{2}-\frac{5}{4}.x-\frac{5}{4}\)
\(x=\frac{5}{4}.x-\frac{5}{4}\)
\(x=x\left(\frac{5}{4}-\frac{5}{4}\right)\)
\(x=x.0\)
\(=>x=0\)