a) \(-\left|2+1\right|-2x=1\)
\(\Leftrightarrow-\left|3\right|-2x=1\)
\(\Leftrightarrow-3-2x=1\)
\(\Leftrightarrow-2x=1-3\)
\(\Leftrightarrow-2x=-2\)
\(\Leftrightarrow x=\dfrac{-2}{-2}=1\)
Vậy x=1
b) \(\left|7x-1\right|-\left|5+6\right|=0\)
\(\Leftrightarrow\left|7x-1\right|-\left|11\right|=0\)
\(\Leftrightarrow\left|7x-1\right|-11=0\)
\(\Leftrightarrow\left|7x-1\right|=11\)
\(\Leftrightarrow7x-1=\pm11\)
\(\Leftrightarrow\left\{{}\begin{matrix}7x-1=11\\7x-1=-11\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}7x=11\\7x=-10\end{matrix}\right.\)
\(\Leftrightarrow\left\{{}\begin{matrix}x=\dfrac{12}{7}\\x=\dfrac{-10}{7}\end{matrix}\right.\)
Vậy \(x=\dfrac{12}{7}\) hoặc \(x=\dfrac{-10}{7}\)
\(a) - \left | 2 + 1 \right | - 2x = 1\)
\(- 3 - 2x = 1\)
\(2x = - 3 - 1\)
2x = - 4
x = - 2
Vậy ......
