a. $2x – (-17) = 15 $
⇒ $2x+17=15$
⇒ $2x=15-17$
⇒ $2x=-2$
⇒ $x=-1$
Vậy $x=-1$
b. $|x - 2| = 8$
⇒ \(\left[ \begin{array}{l}x-2=8\\x-2=-8\end{array} \right.\)
⇒ \(\left[ \begin{array}{l}x=8+2\\x=-8+2\end{array} \right.\)
⇒ \(\left[ \begin{array}{l}x=10\\x=-6\end{array} \right.\)
Vậy $x=-6$ hoặc $x=10$