Find all x such that $5=|x-2|+|x-7|$.
Split this into 3 cases.
\(If \;\;x< 2 \qquad then \qquad 5=2-x+7-x \quad etc\\ If \;\;2\le x\le 7 \qquad then ?\\ If \;\;x>7 \qquad then ?\\\)
You see if you can work it out now.