Question

tìm x biết

Answer 1

Có: 2\(\mid\)3x - 1\(\mid\) + 1 = 5

=> 2\(\mid\)3x - 1\(\mid\) = 4

=>\(\mid\)3x - 1\(\mid\)= 2

=> 3x - 1 = 2 hoặc 3x - 1 = -2

=> 3x = 3 hoặc 3x = -1

=> x = 1 hoặc x = \(\dfrac{-1}{3}\)

Answer 2

\(2\left|3x-1\right|+1=5\\ \Leftrightarrow2\left|3x-1\right|=4\\ \Leftrightarrow\left|3x-1\right|=2\\ \Leftrightarrow\left[{}\begin{matrix}3x-1=2\\3x-1=-2\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}3x=3\\3x=-1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=1\\x=-\dfrac{1}{3}\end{matrix}\right.\)

Vậy \(x=1\) hoặc \(x=-\dfrac{1}{3}\)