\(\)\(|2x+1|=\dfrac{3}{5}\)
\(\Leftrightarrow2x+1=\pm\dfrac{3}{5}\)
\(\Leftrightarrow\left[{}\begin{matrix}2x+1=\dfrac{3}{5}\\2x+1=-\dfrac{3}{5}\end{matrix}\right.\)\(\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{1}{5}\\x=-\dfrac{4}{5}\end{matrix}\right.\)
Tick cho mk nhé , chúc bạn học tốt
\(\Rightarrow\)2x+1\(\in\)\(\left\{\dfrac{3}{5};\dfrac{-3}{5}\right\}\)
\(\Rightarrow+TH1:2x+1=\dfrac{3}{5}\)
2x=3/5-1
2x=-2/5
x=-2/5:2=-1/5
+TH2:2x+1=-3/5
2x=-3/5-1
2x=-8/5
x=-8/5:2=-4/5
VẬY x\(\in\left\{-\dfrac{4}{5};-\dfrac{1}{5}\right\}\)
bạn học tốt nhé
Suy ra :
2x + 1 = 3/5
2x = 3/5 -1
2x = -2/5
x = -2/5 :2
x = -1/5
\(\left|2x+1\right|=\dfrac{3}{5}\)
\(\Rightarrow\left\{{}\begin{matrix}2x+1=\dfrac{3}{5}\\2x+1=-\dfrac{3}{5}\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}2x=\dfrac{3}{5}-1\\2x=-\dfrac{3}{5}-1\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}2x=-\dfrac{2}{5}\\2x=-\dfrac{8}{5}\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}x=-\dfrac{2}{5}:2\\x=-\dfrac{8}{5}:2\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}x=-\dfrac{1}{5}\\x=-\dfrac{4}{5}\end{matrix}\right.\)
Vậy \(x\in\left\{-\dfrac{1}{5};-\dfrac{4}{5}\right\}\)
