Add the values of $$\overline{HK}$$ and $$\overline{KJ}$$. set them equal to $$\overline{HJ}$$ because the smaller line segments make up the larger line segment. $$\overline{HK} + \overline{KJ} = \overline{HJ}$$ $$x-5+5x-12=25$$ solve for $$x$$.