`<=> -3/4 x = 3/22 - 7/11`
`<=> -3/4 x = -1/2`
`<=> x = -1/2 : -3/4`
`<=> x = 2/3`.
Vậy `x = 2/3`.
`b, <=> |4/3 - 0,4 x| = 1/4 + 5/12`
`<=> |4/3 - 0,4x | = 2/3`
`Th1: 4/3 - 0,4 x = 2/3`
`<=> 0,4 x= 2/3`
`<=> x = 2/3 : 0,4 = 5/3`
`Th2: 4/3 - 0,4x = -2/3`
`<=> 0,4 x = 2`
`<=> x = 5`.
\(a,\dfrac{-3}{4}x+\dfrac{7}{11}=\dfrac{3}{22}.\\ \Leftrightarrow\dfrac{-3}{4}x=\dfrac{-1}{2}.\\ \Leftrightarrow x=\dfrac{2}{3}.\)
\(b,\left|1\dfrac{1}{3}-0,4x\right|-\dfrac{5}{12}=\dfrac{1}{4}.\\ \Leftrightarrow\left|\dfrac{4}{3}-\dfrac{2}{5}x\right|=\dfrac{2}{3}.\\ \Leftrightarrow\left[{}\begin{matrix}\dfrac{4}{3}-\dfrac{2}{5}x=\dfrac{2}{3}.\\\dfrac{4}{3}-\dfrac{2}{5}x=-\dfrac{2}{3}.\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{5}{3}.\\x=5.\end{matrix}\right.\)
` b ) | 1 1/3 - 0,4x | - 5/12 = 1/4`
`| 4/3 - 2/5 x | = 1/4 + 5/12`
`| 4/3 - 2/5 x | 2/3`
Trường hợp `1` `:`
` 4/3 - 2/5 x =2/3`
`2/5x=4/3-2/3`
`2/5x=2/3`
`x=2/3:2/5`
`x=5/3`
Trường hợp `2` `:`
`4/3-2/5x=-2/3`
`2/5x=4/3-(-2)/3`
`2/5x=2`
`x=5`
`-` Vậy `x=5/3` hoặc `x=5`
`#Sal_tSea`
a. \(-\dfrac{3}{4}x+\dfrac{7}{11}=\dfrac{3}{22}\\ -\dfrac{3}{4}x=\dfrac{3}{22}-\dfrac{7}{11}\\ -\dfrac{3}{4}x=-\dfrac{11}{22}\\ x=-\dfrac{11}{22}:-\dfrac{3}{4}\\ x=\dfrac{22}{33}\)
------------------------------------------
b. \(\left|1\dfrac{1}{3}-0,4x\right|-\dfrac{5}{12}=\dfrac{1}{4}\\ \left|\dfrac{4}{3}-0,4x\right|=\dfrac{1}{4}+\dfrac{5}{12}\\ \left|\dfrac{4}{3}-0,4x\right|=\dfrac{2}{3}\\ \Rightarrow\left[{}\begin{matrix}\dfrac{4}{3}-0,4x=\dfrac{2}{3}\\\dfrac{4}{3}-0,4x=-\dfrac{2}{3}\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}0,4x=\dfrac{4}{3}-\dfrac{2}{3}\\-0,4x=\dfrac{4}{3}--\dfrac{2}{3}\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{2}{3}:0,4\\x=2:-0,4\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{5}{3}\\x=-5\end{matrix}\right.\)
