Question

3| x – 1| – 5 = 7

Answer 1

3| x - 1| - 5 = 7

3| x - 1| = 7+ 5

3| x- 1| = 12

| x - 1| = 4

=> x - 1 = 4 hoặc x - 1 = -4

x = 5 hoặc x = -3

Vậy x = 5 ; x = -3

Answer 2

\(3\left|x-1\right|-5=7\)

\(\Rightarrow3\left|x-1\right|=7+5\)

\(\Rightarrow3\left|x-1\right|=12\)

\(\Rightarrow\left|x-1\right|=12:3\)

\(\Rightarrow\left|x-1\right|=4\)

\(\Rightarrow\left[{}\begin{matrix}x-1=4\\x-1=-4\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=5\\x=-3\end{matrix}\right.\)

Vậy, \(x\in\left\{-3;5\right\}\)