a,\(\left|x\right|-2=7-\left(-8\right)\)
\(\left|x\right|-2=7+8\)
\(\left|x\right|-2=15\)
\(\left|x\right|=17\)
\(\Leftrightarrow\left[{}\begin{matrix}x=17\\x=-17\end{matrix}\right.\)
Vậy...
b,\(48+5\left(x-3\right)=63\)
\(5\left(x-3\right)=15\)
\(x-3=3\)
\(x=6\)