Question

\(\sqrt{\left(1-2x\right)^2}=9\)

Answer 1

\(\sqrt{\left(1-2x\right)^2}=9\)

<=> \(\sqrt{\left(1-2x\right)^2}=3^2\)

<=> \(\left|1-2x\right|=\left|3\right|\)

<=> \(\left|1-2x\right|=3\)

<=> \(\left[{}\begin{matrix}1-2x=3\\1-2x=-3\end{matrix}\right.\)

<=> \(\left[{}\begin{matrix}x=-1\\x=2\end{matrix}\right.\)

Answer 2

\(\sqrt{\left(1-2x\right)^2}=9\)

\(\Rightarrow\left|1-2x\right|=9\)

\(\Rightarrow\left[{}\begin{matrix}1-2x=9\\1-2x=-9\end{matrix}\right.\)

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

Answer 3

GTTĐ ko cần đk nhé (trừ TH đặc biệt.)