Question

Tìm x

\(\left|3,5-x\right|+\dfrac{2}{7}=\dfrac{16}{7}\)

Answer 1

|3,5-x|\(+\dfrac{2}{7}=\dfrac{16}{7}\)

\(\Leftrightarrow\left|3,5-x\right|=\dfrac{16}{7}-\dfrac{2}{7}\)

\(\Leftrightarrow\left\{{}\begin{matrix}3,5-x=2\\3,5-x=-2\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}1,5\\x=5,5\end{matrix}\right.\)

Answer 2

\(|3,5-x|=\dfrac{16}{7}-\dfrac{2}{7}\)

\(|3,5-x|=2\)

\(\Rightarrow|\left[{}\begin{matrix}3,5-x=2\\3,5-x=-2\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=3,5-2\\x=3,5-\left(-2\right)\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=1,5\\x=5,5\end{matrix}\right.\)

\(\Rightarrow x\in\left\{1,5;5,5\right\}\)