Question

\(\left|\dfrac{1}{2}\chi+2\right|=3\)

Answer 1

\(\left|\dfrac{1}{2}x+2\right|=3\)

\(\Rightarrow\dfrac{1}{2}x+2=3\)

\(\Rightarrow\dfrac{1}{2}x=1\)

\(\Rightarrow x=2\)

Vậy ...........

Answer 2

Từ \(\left|\dfrac{1}{2}x+2\right|=3\)

\(\Rightarrow\left\{{}\begin{matrix}\dfrac{1}{2}x+2=3\\\dfrac{1}{2}x+2=-3\end{matrix}\right.\)\(\Rightarrow\left\{{}\begin{matrix}\dfrac{1}{2}x=3-2\\\dfrac{1}{2}x=-3-2\end{matrix}\right.\)\(\Rightarrow\left\{{}\begin{matrix}x=1:\dfrac{1}{2}\\x=-5:\dfrac{1}{2}\end{matrix}\right.\)\(\Rightarrow\left\{{}\begin{matrix}x=2\\x=-10\end{matrix}\right.\)

Answer 3

\(\left|\dfrac{1}{2}x+2\right|=3\)

\(\Rightarrow\left[{}\begin{matrix}\dfrac{1}{2}x+2=3\\\dfrac{1}{2}x+2=-3\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}\dfrac{1}{2}x=1\\\dfrac{1}{2}x=-5\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=2\\x=-10\end{matrix}\right.\)

vậy \(x\in\left\{2,-10\right\}\)