Question

Tìm x:

\(\sqrt{\left(2x-3\right)^2}-5=0\)

Answer 1

Lời giải:

$\sqrt{(2x-3)^2}-5=0$

$\Leftrightarrow |2x-3|-5=0$

$\Leftrightarrow |2x-3|=5$

$\Leftrightarrow 2x-3=5$ hoặc $2x-3=-5$

$\Leftrightarrow x=4$ hoặc $x=-1$ (đều thỏa mãn)

Answer 2

\(\sqrt{\left(2x-3\right)^2}-5=0\)

\(\Leftrightarrow\left|2x-3\right|=5\)

\(\Leftrightarrow\left[{}\begin{matrix}2x-3=5\\2x-3=-5\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}2x=8\\2x=-2\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=4\\x=-1\end{matrix}\right.\)

Vậy \(S=\left\{4;-1\right\}\)