Question

a)|2 - x| = 2x - 1
b) |-2x| = x - 3 

 

 

Answer 1

a.\(\left|2-x\right|=2x-1\)

\(\Leftrightarrow\left[{}\begin{matrix}2-x=2x-1;x\le2\\x-2=2x-1;x>2\end{matrix}\right.\)  \(\Leftrightarrow\left[{}\begin{matrix}x=1\left(tm\right)\\x=-1\left(ktm\right)\end{matrix}\right.\)

Vậy \(S=\left\{1\right\}\)

b.\(\left|-2x\right|=x-3\)

\(\Leftrightarrow\left[{}\begin{matrix}-2x=x-3;x\le0\\2x=x-3;x>0\end{matrix}\right.\) \(\Leftrightarrow\left[{}\begin{matrix}x=1\left(ktm\right)\\x=-3\left(ktm\right)\end{matrix}\right.\)

Vậy pt vô nghiệm