Question

Answer 1

a: =>|x-1,8|=1,2

=>x-1,8=1,2 hoặc x-1,8=-1,2

=>x=3 hoặc x=0,6

b: \(\Leftrightarrow\left|2x-\dfrac{3}{5}\right|=2\)

=>2x-3/5=2 hoặc 2x-3/5=-2

=>2x=13/5 hoặc 2x=-7/5

=>x=13/10 hoặc x=-7/10

c: \(\Leftrightarrow\left|3x-4\right|=\dfrac{17}{3}\)

=>3x-4=17/3 hoặc 3x-4=-17/3

=>3x=29/3 hoặc 3x=-5/3

=>x=29/9 hoặc x=-5/9

Answer 2

a, | x - 1,8 | + 3 = 4,2

    | x - 1,8 |       = 4,2 - 3

    | x - 1,8 |       = 1,2

=> x - 1,8 = \(\pm\) 1,2 \(\Rightarrow\left\{{}\begin{matrix}x-1,8=1,2\\x-1,8=-1,2\end{matrix}\right.\left\{{}\begin{matrix}x=3\\x=0,6\end{matrix}\right.\)

b, \(\left|2x-\dfrac{3}{5}\right|:\dfrac{1}{6}=12\)

    \(\left|2x-\dfrac{3}{5}\right|=12.\dfrac{1}{6}\)

    \(\left|2x-\dfrac{3}{5}\right|=2\)

\(\Rightarrow2x-\dfrac{3}{5}=\pm2\Rightarrow\left\{{}\begin{matrix}2x-\dfrac{3}{5}=2\\2x-\dfrac{3}{5}=-2\end{matrix}\right.\left\{{}\begin{matrix}x=\dfrac{13}{10}\\x=-\dfrac{7}{10}\end{matrix}\right.\)

c,\(6-\left|4-3x\right|=\dfrac{1}{3}\)

         \(\left|4-3x\right|=6-\dfrac{1}{3}=\dfrac{18}{3}-\dfrac{1}{3}=\dfrac{17}{3}\)

\(\Rightarrow4-3x=\pm\dfrac{17}{3}\Rightarrow\left\{{}\begin{matrix}4-3x=\dfrac{17}{3}\\4-3x=-\dfrac{17}{3}\end{matrix}\right.\left\{{}\begin{matrix}x=-\dfrac{5}{9}\\x=\dfrac{29}{9}\end{matrix}\right.\)

 

 

Answer 3

a)`|x-1,8| +3 =4,2`

`=> |x-1,8| = 7,2`

`=> `\(\left[{}\begin{matrix}x-1,8=7,2\\x-1,8=-7,2\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=9\\x=-5,4\end{matrix}\right.\)

b)\(\left|2x-\dfrac{3}{5}\right|:\dfrac{1}{6}=12\Leftrightarrow\left|2x-\dfrac{3}{5}\right|=2\)

`<=>`\(\left[{}\begin{matrix}2x-\dfrac{3}{5}=2\\2x-\dfrac{3}{5}=-2\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}2x=\dfrac{13}{5}\\2x=-\dfrac{7}{5}\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{13}{10}\\x=\dfrac{-7}{10}\end{matrix}\right.\)

c)`6-|4-3x| = 1/3`

`=> |4-3x| = 6-1/3 = 17/3`

\(\Leftrightarrow\left[{}\begin{matrix}4-3x=\dfrac{17}{3}\\4-3x=-\dfrac{17}{3}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}3x=-\dfrac{5}{3}\\3x=\dfrac{29}{3}\end{matrix}\right.\)

`=>`\(\left[{}\begin{matrix}x=-\dfrac{5}{9}\\x=\dfrac{29}{9}\end{matrix}\right.\)