Question

3I2x-3I=I-10+31I

I là dấu giá trị tuyệt đối

Answer 1

Ta có: \(3\left|2x-3\right|=\left|-10+31\right|\)

\(\Leftrightarrow3\left|2x-3\right|=21\)

\(\Leftrightarrow\left|2x-3\right|=7\)

\(\Leftrightarrow\left[{}\begin{matrix}2x-3=7\\2x-3=-7\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}2x=10\\2x=-4\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=5\\x=-2\end{matrix}\right.\)

Vậy: \(x\in\left\{5;-2\right\}\)

Answer 2

\(3\left|2x-3\right|=\left|-10+31\right|\)

\(\Rightarrow3\left|2x-3\right|=21\)

\(\Rightarrow\left|2x-3\right|=7\) \(\Rightarrow\left[{}\begin{matrix}2x-3=7\\3-2x=7\end{matrix}\right.\) \(\Rightarrow\left[{}\begin{matrix}x=5\\x=-2\end{matrix}\right.\)

Vậy \(x\in\left\{5;-2\right\}\)