a/ \(\Leftrightarrow x-3=25\Rightarrow x=28\)
b/ \(\Leftrightarrow3x=45\Leftrightarrow x=9\)
c/ \(\Leftrightarrow\left|2x+1\right|=10\Leftrightarrow\left[{}\begin{matrix}2x+1=10\\2x+1=-10\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=\frac{9}{2}\\x=-\frac{11}{2}\end{matrix}\right.\)